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155 Cards in this Set
- Front
- Back
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Cerebral edema--intracellular type
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-decreased serum Na+ (SIADH)
-dysfunctional Na+/K+ ATPase pump (global hypoxia) |
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Cerebral edema--extracellular type
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-increased vessel permeability
-causes include meningitis and metastasis |
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Head trauma
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-pt hyperventilates to produce respiratory alkalosis which causes cerebral vessel constricition
-respiratory acidosis and hypoxemia increases cerebral vessel permeability which enhances the cerebral edema |
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Papilledema
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-swelling of optic disc
-sign of cerebral edema |
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Intracranial HTN
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-papilledema, bradycardia, projectile vomiting, hypertension
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Pseudotumor cerebri
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-benign intracranial HTN
-increased intracranial pressure without evidence of tumor or obstruction -most common in young, obese women -decreased CSF resorption in arachnoid granulations -symptoms include headache, blurry vision, diplopia |
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Cerebral herniation
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-complication of intracranial HTN
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Subfalcine herniation
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-compression of anterior cerebral artery (ACA)
-cingulate gyrus herniates under falx cerebri |
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Uncal Herniation
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-medial portions of temporal lobe herniates through tentorium cerebelli
-compresses CN 3, posterior cerebral artery (causes hemorrhage of occipital lobe), and parasympathetic fibers |
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Uncal herniation
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-eye is deviated down and out
-mydriasis (dilated pupil) |
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Tonsilar herniation
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-cerebellar tonsils herniate into foramen magnum
-causes "coning" of cerebellar tonsils -produces cardorespiratory arrest |
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Hydrocephalus
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-enlargement of ventricles due to increase of CSF volume
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CSF
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-produced by choroid plexus
-reabsorbed by arachnoid granulations |
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Bloody CSF
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-most commonly iatrogenic
-can also represent a hemorrhage into the subarachnoid space -in pathologic instances, CSF is pink after centrifugation |
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CSF protein
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-normally 15-45 mg/dl
-if increased it indicates increased capillary permeability |
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CSF gamma (y) globulins
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-derive from the synthesis of IgG by plasma cells
-an increase in IgG indicates either multiple sclerosis of meningitis |
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Oligoclonal bands
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-from single clones of immunocompetent B cells
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Increased myelin basic protein (MBP)
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-indicates a demyelinating disease
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CSF glucose
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-normal value is 50-75
-CSF glucose under 40 occurs in acute bacterial meningitis, malignant cells, fungal meningitis -CSF glucose is normal in viral meningitis, neurosyphilis, demyelinating disease and a cerebral absecess -exceptions where CSF glucose is decresed is with mumps, herpes, and lymphocytic choriomeningitis virus |
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CSF white blood cell count
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-normally 0-5 mononuclear cells
-neutrophils in CSF are never normal -an increased WBC is most often due to bacterial meningitis -bacteria meningitis has a predominance of neutrophils while viral meningitis initially has a neutrophil response in the first 24 hours that changes to a mainly lymphocytic response in 2-3 days -fungal meningitis has mainly lymphocytes and monocytes |
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Communicating hydrocephalus
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-increased production of CSF
-decreased resorption of CSF |
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Noncommunicating hydrocephalus
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-obstruction of CSF outflow into ventricles
-most common cause of hydrocephalus in newborns is blockage of aqueduct of Sylvius |
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Hydrocephalus in children
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-ventricles dilate and enlarge head circumference
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Hydrocephalus in adults
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-no increase in head size
-dementia, gait disturbance, urinary incontinence |
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Hydrocephalus ex vacuo
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-dilated appearance of the ventricles when the brain mass is decreased
-ex: Alzheimers disease |
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Normal pressure hydrocephalus
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-Dilated ventricles + triad (dementia, urinary incontinence, wide-based gait)
-it is a potentially reversible cause of dementia with shunting -wide-based gait and urinary incontinence is due to stretching of sacral motor fibers -dementia is due to stretching of the limbic fibers |
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Neural tube defects
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-failure of fusion of lateral folds of neural plate
-increased a-fetoprotein -maternal folate level must be adequate before pregnancy |
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Anacephaly
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-absence of brain
-maternal polyhydraminos |
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Spina bifida occulta
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-dimple/tuft of hair overlying L5-S1
-defect in closure of posterior vertebral arch |
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Meningocele
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-cystic mass with meninges
-msot common in lumbosacral region |
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Meningomyelocele
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-cystic mass with meninges and spinal cord
-most common in lumbosacral region |
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Arnold-Chiari malformation
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-caudal extension of medulla and cerebellar vermis thorugh foramen magnum
-noncommunicating hydrocephalus -associated with meningomyelocele and Syringomyelia |
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Dandy-Walker Malformation
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-Partial or complete absence of cerebellar vermis
-Cystic dilation of 4th ventricle -noncommunicating hydrocephalus |
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Syringomyelia
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-degenerative disease of spinal cord
-fluid-filled cavity in cervical spinal cord -causes cervical cord enlargement -decreased pain/temp sensation in hands -loss of intrinsic muscles of hand -MRI shows cervical enlargement and cavity |
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Phakomatoses (neurocutaneous syndromes)
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-neurocutaneous sundromes, disordered growth of ectodermal tissue, malformations or tumors of CNS
-includes Neurofibromatosis, tuberous sclerosis, Sturge-Weber syndrome |
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Neurofibromatosis
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-autosomal dominant with incomplete penetrance
-Type 1 is most common -NF1 has mutation on chromosome 17 coding for neurofibromin -NF2 has mutation on chromosome 22 coding for merlin |
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Both NF1 and NF2
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-cafe au lait macules
-neurofibromas |
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NF1
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-optic gliomas
-Lisch nodules (hamartoma of the iris) -axillary/inguinal freckling -associated with pheochromacytoma, Wilm's tumor, and juvenile Chronic myelogenous leukemia (CML) |
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NF2
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-bilateral acoustic neuromas (schwannoma)
-juvenile cataracts -meningiomas |
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Tuberous Sclerosis
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-autosomal dominant
-causes mental retardation -hamartomas in brain and kidneys -triad of seizures, mental retardation, angiofibromas, ash leaf lesions (hypopigmented) -rhabdomyoma of heart is highly predictive of TS |
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Sturge-Weber Syndrome
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-Vascular malformation on the face
-some pt's have ipsilateral arteriovenous malformation in the meninges |
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Coup injuries
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-site of impact
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Contrecoup injuries
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-opposite side of impact
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Epidural hematoma
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-caused by a fracture of the temporoparietal bone
-tear of middle meningeal artery -CT scan is imaging test of choice |
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Subdural hematoma
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-venous bleed between dura and arachnoid memrbanes
-most often caused by trauma -increased risk of cerebral atrophy -tearing of bridging veins produce venous blood clot -CT scan is imaging test of choice |
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Global hypoxic injury
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-causes include hypotensive episodes, cardiac arrest, hypovolemic shock, chronic carbon monoxide poisoning
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Hypoglycemia
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-have same effects on brain as does global hypoxic injury
-occurs in diabetes 1 |
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Complications of global hypoxic injury
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-cerebral atrophy
-watershed infarcts -stroke |
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Red neurons
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-apoptotic neurons that occur from global hypoxic ischemia
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Strokes
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-increased incidence with age
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Atherosclerotic stroke
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-most common stroke overall
-ischemic type of stroke due to thrombosis -causes pale infarcts (liquefactive necrosis) that extends to periphery of cerebral cortex -most occurs in distribution of middle cerebral artery (MCA) -infarction if liquefactive not coagulative necrosis! |
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TIA
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-transient neurologic deficit lasting <24 hours
-most atherosclerotic strokes are preceded by TIAs -usually caused by microembolism of plaque material -deficits that do not resolve within 24 hours are called strokes |
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Amaurosis fugax
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-temporary loss of vision due to embolization of atherosclerotic material trapped at bifurcation of retinal arteries
-called Hollenhorst plaque |
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Middle Cerebral Artery (MCA) stroke
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-causes contralateral paresis and sensory loss in the face and upper extremity
-head and eyes deviate to side of lesion |
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Anterior Cerebral Arerty (ACA) stroke
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-causes contralateral paresis and sensory loss in lower extremity
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Embolic (hemorrhagic) stroke
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-ischemic type of stroke due to embolization
-source of emboli most often come from left side of heart -produces a hemorrhagic infarction extending to the periphery of the cerebral cortex |
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Intracerebral hemorrhage
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-most often due to stress imposed on vessels by HTN
-can be caused by rupture of aneurysms -Treatment: HTN reduction reduces risk of strokes by more than 40% |
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Most common site of intracerebral hemorrhage
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-basal ganglia (putamen)
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Subarachnoid hemorrhage
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-majority are due to rupture of a congenital berry aneurysm
-severe occipital headache -described as "worst headache ever" |
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Congenital berry aneurysms
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-most develop at junctions of communicating branches with main cerebral artery
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Lacunar infarcts
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-cystic areas of microinfarction <1 cm in diameter
-caused by hyaline arteriolosclerosis due to HTN/diabetes |
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Diagnosis of strokes
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-CT without contrast is best test
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CNS infections
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-most are due to sepsis
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Meningitis
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-inflammation of pia mater
-sign of meningitis is nuchal rigidity |
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Bacterial meningitis
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-usually due to hematogenous spread
-majority of organisms orgininate in nasopharynx |
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Viral meningitis
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-most often transmitted by fecal-oral route
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Lab findings in meningitis
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-Increased CSF protein (viral, bacterial, fungal)
-Decreased CSF glucose (bacterial, fungal) |
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CSF in bacterial/fungal meningitis
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-1000-20,000 cells
->90% neutrophils -decreased CSF glucose -Increased CSF protein -Positive gram stain |
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CSF in Viral meningiits
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-less than 1000 cells
-first 24-48 hours is neutrophils then switches to lymphocytes/monocytes after 48 hours -normal CSF glucose except in mumps, herpes -increased CSF protein -negative gram stain |
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Encephalitis
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-inflammation of brain
-causes headache, drowsiness, and coma |
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Cerebral abscess
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-hematogenous, contiguous spread such as from sinuses or infective endocarditis
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Demyelination
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-destruction of normal myelin: multiple sclerosis
-destruction of abnormal myelin: leukodystrophy -destruction of oligodendrocytes: multiple sclerosis, slow virus infections |
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Multiple Sclerosis
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-msot common demyelinating disease
-CD4 T cells react against self antigens in myelin sheath -cytokines activate macrophages that destroy myelin -genetic factors and environmental triggers -demylinating plaques: white matter looks like gray matter -autonomic dysfunction: urge incontinence; sexual dysfunction, bowel motility dysfunction -blurry vision due to optic neuritis; MS is most common cause of optic neuritis -SIN: scanning speech, intention tremor, nystagmus -Bilateral internuclear opthalmoplegia (INO): demylination of MLF; pathognomic for MS -Lab findings: increased CSF lymphs, CSF protein, CSF MBP; normal CSF glucose -oligoclonal bands in high-resolution electrohoresis: sign of demyelination |
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Central Pontine Myelinolysis
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-most often occurs in alcoholics who have hyponatremia
-due to rapid IV correction of hyponatremia |
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Arboviruses
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-causes encephalitis
-mosquitos are vector -wild birds are resevoir -West Nile Virus: crows/birds |
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Coxsackievirus
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-causes meningitis
-enterovirus is most common cause of viral meningitis -viral meningiits peaks in late summer and early autumn |
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Cytomegalovirus
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-causes encephalitis
-most common viral CNS infection in AIDS -intranuclear basophilic inclusions -periventricular calcification in newborns |
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Herpes Simplex Type 1
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-causes meningitis and encephalitis
-causes hemorrhagic necrosis of temporal lobes |
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HIV
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-causes encephalitis
-most common cause of AIDS dementia -microglial cells fuse to form multinucleated cells |
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Lymphocytic choriomeningitis
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-causes meningitis and encephalitis
-endemic in mice -transmission via food/water contaminated with mouse feces/urine -meningoencephalitis: combination of nuchal rigidity and mental status abnormalities (encephalitis) -CSF findings: increased protein, lymphocyte infiltrate, normal to decreased glucose |
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Poliovirus
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-causes encephalitis and myelitis--spinal cord
-destroys upper and lower motor neurons -causes muscle paralysis -Post-polio syndrome: occurs in 50% of people with previous poliomyelitis; usually occurs 15-30 years after original infection; increased muscular weakness/pain in muscle groups already affected; excessive fatigue |
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Rabies Virus
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-causes encephalitis
-most often transmitted via raccoon bite -other vectors are dog, skunk, bat, coyote -viral receptor is acetycholine receptor -initially replicates at site of bite; moves by axonal transport to the CNS; after CNS replication it migrates to saliva -animal transmits virus when in agitated state (encephalitis stage) -Prodrome: fever, paresthesias in and around wound site -Hydrophobia: due to spasms of throat muscles when swallowing follwed by flaccid paralysis -encephalitis: death of neurons; eosinophilic intracytoplasmic inclusions called Negri bodies; seizures, coma, death |
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Creutzfeldt-Jakob Disease
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-Fatal encephalopathy due to prions (proteinaceous material lacking RNA and DNA)
normal prion protein (PrP) in neuronal membranes misfolds, becomes infectious, and results in death of neurons and spongiform change (cytoplasmic vascuoles; "bubbles and holes") -transmission via corneal implants, grafts of dura mter, contaminated deep implantation electroes, ingestion of contaminated beef from cattle (mad cow disease) -causes severe dementia and death within 1 year |
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Progressive multifocal leukoencephalopathy
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-convential slow virus encephalitis due to papovirus
-intranuclear inclusion in oligodendrocytes -occurs in AIDS when CD4 T count <50 cells |
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Subacute sclerosing panencephalitis
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-Convential slow virus encephalitis associated with rubeola (measles) virus
-intranuclear inclusions in neurons and oligodendrotcytes -death in 1-2 years |
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Group B Streptococcus (streptococcus agalactiae)
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-causes neonatal meningitis
-gram-positive coccus -most common cause of neonatal meningiits -spreads from infection in maternal vagina |
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E. coli
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-causes neonatal meningiits
-gram-negative rod -2nd most common cause of neonatal meningitis |
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Listeria Monocytogenes
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-causes neonatal meningitis
-gram-positive rod with tumbling motility; actin rockets help organism to move from cell to cell -pathogen found in soft cheese, hot dogs |
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Neisseria meningitidis
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-causes meningitis
-gram-negative diplococcus; locates in posterior nasopharynx -most common cause of meningitis in those between 1 month-18 years old |
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Streptococcus pneumoniae
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-causes meningitis
-gram-positive diplococcus -most common cause of meningitis in patients >18 years old |
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Mycobacterium tuberculosis
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-causes meningitis
-complication of primary tuberculosis -involves base of brain -vasculitis (infarction) and scarring (hydrocephalus) |
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Treponema pallidum
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-causes meningiits, encephalitis, myelitis
-spirochete -types of neurosyphilis: 1. Meningovascular: vasculitis causing strokes 2. General Paresis: dementia 3. Tabes dorsalis: involves posterior root ganglia and posterior column; causes ataxia, loss of vibration sense, absent deep tendon reflexes, Argyll-Robertson pupil (pupils accomodate but do not react) |
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Cryptoccous neoformans
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-causes meningiits and encephalitis
-ocurs in immunocompromised -most common fungal CNS infeciton in AIDS -budding yeasts visible with India Ink |
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Mucor
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-causes frontal lobe abscess
-occurs in diabetic ketoacidosis -spreads from frontal sinuses |
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Naegleria fowleri
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-causes meningoencephalitis
-protozoa (ameoba) -involves frontal lobes -contracted by swimming in freshwater lakes |
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Trypansoma gambiense/ rhodesiense
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-causes encephalitis
-protozoa (hemoflagelalte) -transmission via bite of an infected tsetse fly (Glossina) -Trypanosomes invade the blood and lymph early in disease; initial drainage into posterior cerivical nodes produces lymphadenopathy (Winterbottom's sign); encephalitis occurs in late stages -Diffuse encephalitis: somnolence (sleeping sickness) due to release of sleep mediators by organism -Trypanosoms are capable of antigen variation (cyclical fever spikes) -starvation is most common cause of death -Diagnosis: trypanosomes in blood, CSF; increase in IgM early in disease |
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Taenia solium
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-produces cysticercosis
-helminth (tapeworm; cestode); pig transmitted disease -Pt ingests food or water containing eggs; eggs develop into larval forms (cysticerci) that invade brain -produces calcified cysts in brain causing seizures and hydrocephalus |
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Toxoplasma gondii
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-causes encephalitis
-protozoa (sporozoan) -most common CNS space-occupying lesion in AIDS -ring-enhancing lesions on CT -congential toxoplasmosis produces basal ganglia calcification |
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Adrenoleukodystrophy
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-X-linked recessive disorder
-enzyme deficinecy in B-oxidation of fatty acids in peroxisomes -results in accumulation of long-chain fatty acids -causes loss of myelin in brain and adrenal insufficiency |
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Metachromatic leukodystrophy
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-Lysosomal storage disesae
-deficiency of arylsulfatase A -results in accumulation of sulfatides |
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Krabbe's disease
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-Lysosomal storage disorder
-Galctocerebroside B-galactocerebrosidase deficiency -leads to accumulation of galactocerebroside |
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Alzheimer's disease
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-most common overall cause of dementia
-sporadic late onset type is most common type -prevalence increases with age -Phosphoryylated B-amyloid (AB) is neurotoxic -activated glycogen synthase kinase-3B (GSK) phosphorylates AB adding to its neurotoxicity -AB can be converted into amyloid which deposits in cerebral vessels |
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AB
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-stains positive with Congo red and has apple-green birefringence
-a metabolic product of APP on chromosome 21 -defects in metabolism of APP by secretases causes an increase in AB -B secretases followed by Y secretases cleave APP into fragments that are converted to AB -a-secretases cleave APP into fragments that can't produce AB |
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Insulin degrading enzyme
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-involved in clearance of AB
-insulin-resistance syndromes (type 2 diabetes, metabolic syndrome) have increased risk for Alzheimers |
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Tau protein in Alzheimers
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-normal function is to maintain microtubules in neurons
-activated GSK-3B hyperphosphorylates tau protein which causes the protein to change shape and cluster into fibers -fibers appear as neurofibrillary tangles |
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ApoE4
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-leads to sporadic early onset of Alzheimers
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PIN 1 enzyme
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-dephosphorylates hyperphosphorylated tau protein
-deficient in some cases of Alzheimers |
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Alzhimers dementia
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-increased density of neurofibrillary tangles (hyperphosphorylated tau protein) and senile (neuritic) plaqes in the brain
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Senile (neuritic) plaques
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-core of AB surrounded by neuronal cell processes containing tau protein, microglial cells, and astrocytes
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Amyloid Angiopathy
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-AB is present in cerebral vessels
-causes weakening of vessesls with increased risk for hemorrhage |
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Confirmation of Alzheimers
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-must be made at autopsy
-must be widespread presence of NF tangles and senile plaques |
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Prominent early sign in Alzheimer's
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-decline in short term memory
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Presumpative diagnosis of Alzheimers
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-mental status testing and ruling out all other causes of dementia
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Parkinsonism
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-alteration in dopaminergic pathways involved in voluntary muscle movement
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Dopamine
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-main neurotransmitter in nigrostriatal tract
-connects substantia nigra with caudate and putamen |
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Ideopathic Parkinson's disease
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-most common cause of Parkinsonism
-there is depigmentation of substantia nigra neurons due to decreased dopamine -clinical findings include rigidity, resting tremor, bradykinesia (slowness of voluntary muscle movement) -expressionless face -blepharospasm -seborrheic dermatitis |
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Huntington's Disease
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-autosomal dominant
-trinculeotide repeat disorder (CAG) involving chromosome 4 -atrophy of caudate nucleus, putamen and globus pallidus -symptoms include chorea, oculomotor abnormalities |
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Friedrich's ataxia
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-autosomal recessive
-trinucleotide repeat disorder (GAA) -Frataxin deficiency: leads to impaired mitochondrial iron homeostasis and cells are more prone to apoptosis -degeneration sites: Dorsal root ganglia, posterior/spinocerebellar/corticospinal tracts -associated with hypertrophic cardiomyopathy and type 1 diabetes |
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Lou Gehrig's Disease (Amytrophic lateral sclerosis)
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-degeneration of upper and lower motor neurons
-atrophy of intrinsic muscles of hand (first LMN sign) -no sensory changes -bowl and bladder function intact |
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Werdnig-Hoffman Disease
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-LMN disease in children
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Wilson's Disease
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-Cystic degeneration of putamen
-defect in copper excretion in bile and defect incorporation of copper into ceruloplasmin |
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Lenticular nucleus
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-putamen + globus pallidus
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Acute Intermittent Porphyria
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-defect in porphyrin metabolism
-deficiency of uroporphyrinogen synthase (porphobilinogen deaminase) -increase in porphobilinogen (PBG) and aminolevulinic acid -urine is colorless when first voided; exposure to light produces color -causes bellyful of scars, peripheral neuropathy and dementia -treatment: carbohydrate loading which inhibits ALA synthase |
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Vit. B12 deficiency
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-aubacute combined degeneration of spinal cord
-causes dementia |
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Wernicke-Korsakoff Syndrome
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-due to thiamine deficiency
-hemorrhages in mamillary bodies |
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Wernicke's encephalopathy
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-confusion, ataxia, nystagmus, opthalmoplegia (eye muscle weakness)
-to prevent: supplement alcoholics IV infusion of glucose with thiamine |
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Most common primary CNS tumor in adults?
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Glioblastoma multiforme
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Primary brain tumors in adults
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-most often occur above tentorium cerebelli
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Childhood tumors
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-most often occur below the tentorium cerebelli
-1. Cystic astrocytoma -2. Medulloblastoma -both in cerebellum |
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Clinical findings of brain tumors
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-headache, seizures, intracranial HTN
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Astrocytoma
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-most common neuroglial tumor
-involves frontal lobe in adults -involves cerebellum in children |
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Glioblastoma multiforme
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-grade 4 astrocytoma
-often crosses corpus callosum -hemorrhagic tumor with areas of necrosis and cystic degeneration |
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Meningioma
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-most common benign brain tumor in adults
-female predominance -associated with neurofibromatosis and history of radiation -Psammoma bodies (calcified bodies) |
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Ependymoma
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-benign tumor derived from ependymal cells
-located in 4th ventricle in children -located in cauda equina in adults |
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Medulloblastoma
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-malignant small cell tumor of cerebellum
-mainly occurs in children |
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Oligodendroglioma
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-benign tumor derived from oligodendrocytes
-mainly in adults -frontal lobe calcifications |
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Primary CNS Lymphoma
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-occurs in AIDS
-EBV-mediated cancer |
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Metastasis
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-most common brain malignancy
-1. Lung -2. Breast -3. Skin -4. Kidney -5. GI Tract |
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Sensory changes
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-demyelination
-paresthesias -"glove and stocking" pattern |
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Motor changes
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-axon degeneration
-muscle fasiculations -muscle atrophy |
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Charcot-Marie-Tooth disease
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-most common hereditary neuropathy
-causes atrophy of lower legs -legs have "inverted bottle" appearance |
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Guillan-Barre Syndrome
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-most common acute peripheral neuropathy
-mainly motor involvement -preceding infections: Mycoplasma pneumoniae, Campylobacter jejuni enteritis, viruses (HIV, EBV, CMV, influenza) -causes ascending paralysis -Treatment: IV immunoglobulin or plasma exchange |
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Diabetes Mellitus
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-most common cause of peripheral neuropathy
-due to osmotic damage of Schwann cells |
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Ideopathic Bell's Palsy
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-facial muscle paralysis due to inflammation of CN 7
-Herpes simplex virus is most common association -UMN Bell's Palsy: contralateral weakness of lower face sparing the upper face -LMN Bell's Palsy: Ipsilateral weakness of upper and lower face |
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Drugs producing peripheral neuropathy
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-vincrtistine, hydralazine, phenytoin
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Vitamin deficiencies producing peripheral neuropathy
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-thiamine, pyridoxine, Bit. B12
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Schwannoma (neurilemoma)
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-benign tumor of Schwann cells
-CN 5 and 8 may be involved |
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Acoustic Neuroma
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-Scwannoma of CN 8
-located in cerebellopontine angle -associated with NF2 |
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Ulnar Nerve Injury
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-C8-T1
-fracture of medial epicondyle of humerus -claw hand (loss of interossesous muscles) |
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Radial Nerve Injury
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-C5-T1
-Midshaft fracture of humerus -draping the arm over a park bench ("Saturday Night Palsy") -wrist drop |
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Axillary Nerve Injury
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-C5-C6
-fracture of surgial neck of humerus; anterior dislocation of shoulder joint -can't abduct arm to horizontal position or hold the horizontal position when a downward force is applied (paralysis of deltoid) |
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Median Nerve Injury (C6-T1)
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-most commonly due to entrapment in transverse carpal ligament of wrist or between the bellies of the pronator teres muscle
-2 most common causes are rheumatoid arthritis and pregnancy -nocturnal pain; pain, numbness or paresthesias in thumb, index finger, 3rd finger, and radial side of 4th finger -"ape hand" -difficulty opposing the thumb with the 5th finger -Tinel's sign: pain reproduced by tapping over median nerve -Phalen's sign: pain reproduced with forced flexion of wrist for 1 min |
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Common Peroneal Nerve Injury
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-L4-S2
-common peripheral neuropathy, lead poisoning, fractured neck of fibula, cast tightness -loss of foot eversion due to weakened peroneus longus and brevis -loss of foot dorsiflexion due to weakened tibilias anterior; produces "slapping gait" or "high-stepping gait" -loss of toe extension due to weakened extendor digitorum longus and hallucis longus -all of this produces deformity of plantar flexion with food drop and inversion of foot -sensory deficits in anterolateral aspect of leg and dorsum of foot -loss of ankle jerk reflex |
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Erb-Duchenne palsy
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-Brachial plexus lesion involving C5 and C6
-"waiter's tip deformity" |
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Acoustic neuroma
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-tinnitus and sensorineural hearing loss
-schwannoma of CN 8 |
