differential for weakness -plexus-

I hope you find this file helpful for student preparation for the Neurology Shelf Exam.  I apologize for the intermittent beeps during the audio clips (these will be recorded again soon). Use of the accompanying transcriptions is advisable.

Sincerely,Heather Anderson, MDDirector, Neurology ClerkshipAssociate Professor of Neurology

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Differential for Weakness-Plexus-

• Brachial plexus

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Differential for Weakness-Plexus-

• Lumbosacral plexus

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Differential for Weakness-Peripheral Nerve-

• Upper extremity– Median nerve– Ulnar nerve– Radial nerve

• Lower extremity– Peroneal nerve

Differential for Weakness-Neuromuscular Junction-

• Myasthenia gravis

• Lambert Eaton

Differential for Weakness-Muscle-

• Myopathy (inflammatory, endocrine and electrolyte disorders, metabolic myopathies, drugs and toxins, and infections

• Rhabdomyolysis

• Neuroleptic malignant syndrome

• Serotonin syndrome

Sensory Loss

• Review dermatomal distribution

www.backpain-guide.com/Chapter_Fig_folders/Ch06_Path_Folder/4Radiculopathy

Sensory LossSensory distribution of major peripheral nerves

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Deficits/Findings withFrontal Lobe Lesion

• Contralateral weakness

• Urinary incontinence w/ bilateral lesions

• Expressive aphasia

• Executive dysfunction, personality changes (prefrontal)

Deficits/Findings withParietal Lobe Lesion

• Contralateral sensory loss• Inferior quadrantanopia• Apraxia (dressing, construction,

ideomotor)• Agnosia, agraphia, acalculia, R-L

disorientation (Gerstmann’s syndrome - left parietal lobe)

• Double simultaneous stimulation (left parietal lobe)

• Neglect, apraxia, anosagnosia (denial of deficits) (right parietal)

• Balint’s syndrome (bilateral parietal lobe)– Inability to voluntarily control the

gaze (ocular apraxia)

– Inability to integrate components of a visual scene (simultanagnosia)

– Inability to accurately reach for an object with visual guidance (optic ataxia)

Deficits/Findings withTemporal Lobe Lesion

• Receptive aphasia (dominant laterosuperior)– Sensory amusia, sensory aprosodia (nondominant laterosuperior)

• Superior quadrantanopia• Kluver-Bucy (bitemporal tip) (hyperorality, hypersexuality, etc)• Amnesia (inferomedial aspect – amygdale, hippocampus)• Impaired recognition of facial emotional expression (nondominant

lateroinferior)

Deficits/Findings withOccipital Lobe Lesion

• Homonymous hemianopsia

• Macular sparing – watershed area, supplied by terminal branches of PCA and MCA

Deficits/Findings withBrainstem Lesion

• Be familiar with Wallenberg syndrome– Lesion of lateral medulla – PICA or vertebral– Loss of pain and temperature on ipsilateral face

and contralateral limbs and trunk– Loss of vibration, proprioception, ataxia in

ipsilateral limbs– Ipsilateral Horner's syndrome, vertigo, nystagmus,

hoarseness, and dysphagia are often present

Visual Field Cuts

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