Acute Peripheral Neurological Lesions

George Filiadis, D. O.

November 17, 2005

Peripheral Nervous System

• Serves sensory, motor, and autonomic functions• Sensory symptoms-numbness, tingling,

dysesthesias, pain, and ataxia, due to proprioceptive dysfunction

• Motor symptoms-weakness• Autonomic symptoms-orthostatic symptoms,

bowel or bladder dysfunction, gastroparesis, and sexual dysfunction.

Peripheral Nervous System

• In peripheral nerve process there is reduction or absence of reflexes.

• When the sensory component is involved, test for proprioception, vibratory sensation, and pain and temperature sensibility

• When the motor system is involved there is wasting, fasciculations, and weakness.

• Autonomic dysfunctions may cause anhidrosis, pupillary dysfunction, orthostatic hypotension, and tachy- and bradyarrhythmias.

Localization of neurological disease

• See Figure 233-1• Most muscle-related processes result in weakness of

large proximal muscles along as pain, tenderness, and elevation of CK.

• Diseases that affect other components of the peripheral nervous system seldom cause tenderness and elevation of CK.

• Neuromuscular junction processes can affect large proximal muscles and affect bulbar musculature resulting in pupillary dysfunction, diplopia, dysarthria, or dysphagia.

Myopathies

• Polyomyositis-Inflammatory myopathy-chronic complaints of proximal symmetric weakness-may have muscle pain and tenderness-may have dysphagia and few progress to respiratory failure-no sensory loss, reflexes should be intact

Polyomyositis

• Management-should be assessed for potential respiratory compromise and aspiration risk.-long term treatment-immunosuppressive

agents such as steroids and methotrexate• Differential diagnosis includes Lambert-Eaton

myasthenic syndrome, inclusion body myositis, toxic myopathies, and dermatomyositis.

Myopathies

• Dermatomyositis-Can affect children-similar to polyomyositis except for violaceous rash over face and hands-muscle weakness-no sensory or reflex abnormalities-treatment is immunosuppression-elevated sed rate and CPK

Other Myopathies

• Drug induced –see table 233-1

• Viral myositis causes an acute myopathy involving the heart, associated with febrile illness, myalgia, and elevated CK levels.

• Suspect trichinosis in pt with myalgias, proximal and bulbar muscle weakness, facial edema, and eosinophilia.

Disorders of the Neuromuscular junction- Botulism

• Ingestion of food contaminated with Clostridium botulinum.

• Adults often report exposure to home canned foods

• Infants exposure to honey• Bulbar weakness• Exraoccular movements are sometimes

abnormal

Botulinism

• Absence of pupillary light reflex

• Proximal limb weakness

• Sensation is intact, normal mentation, reflexes are usually normal

• Treatment-antibiotics in infants and immune serum and admission to the hospital

Guillain-Bare Syndrome

• Most common form of acute generalizedneuropathy

• Patients often report recent viral illness, especially gastroenteritis

• Associated with Campylobacter jejuni

Guillain-Barre Syndrome

• Numbness and tingling of the lower extremities followed by weakness of the legs and then arms.

• Weakness more pronounced in the legs• Lack of deep tendon reflexes• May be facial weakness involving the forehead• Chance of respiratory failure and lethal autonomic

fluctuations

Guillain-Barre Syndrome

• Management-Lumbar puncture (high CSF protein,

nl cell count and glucose)-Should be admitted for monitoring-When vital capacity is under 1 liter, intubate.-Plasma exchange or IV immunoglobulin

Focal neuropathies-Carpal Tunnel Syndrome

• Most commonly see entrapment neuropathy.

• Intermittent pain and/or numbness in the thumb and first two fingers.

• Symptoms reproduced with compression of the nerve over the carpal tunnel or by tapping over the nerve.

• Treatment-wrist splints and ortho referral

Focal neuropathies

• Ulnar neuropathy-Numbness of the fourth and fifth fingers

-weakness and wasting of hypothenar eminence is late finding

• Entrapment of deep peroneal nerve-at the fibular head causing foot drop

and numbness of the web between great and second toe

Focal Neuropathies

• Meralgia paresthetica-entrapment of lateral femoral

cutaneous nerve of the thigh.-numbness and

dysesthesias on lateral aspect of upper leg. -usually after weight loss or pelvic procedures

Focal neuropathies

• Mononeuritis multiplex-multiple nerve dysfunctions

caused by vasculitis-usually affects both

sides of the body -differential diagnosis includes multiple compression neuropathies and multifocal motor neuropathy

Focal Neuropathies-Bell’s Palsy

• Most common cause of acute facial paralysis

• Sudden facial weakness, difficulty with articulation, problems keeping an eye closed, or inability to keep food in the mouth one side.

• One sided weakness of the face involving the forehead

Bell’s Pulsy

• Treatment-acyclovir

-Steroid controversial-Eye care to avoid corneal

abrasions -lacrilube and patching

Focal neuropathies-Lyme disease

• Multiple neurologic manifestations

• Arthralgias and fatique initially

• Common neurologic sign is seventh nerve pulsy

• Weakness in the limbs

• May see selected decreased deep tendon reflexes

Lyme Disease

• Management-serum and CSF lyme antibodies

-CSF pleocytosis and increased protein with a normal glucose -treat with 3 week course of IV antibiotics either rocephin or doxycycline

Plexopathies-Brachial Neuritis

• Affects younger individuals• Excruciating back, shoulder, or arm pain

followed by weakness of arm or shoulder girdle.

• On exam there is weakness along the distribution of brachial plexus.

• Differential diagnosis includes cervical radiculopathies, Pancoast tumor

Plexopathies-lumbar

• Occurs in diabetic patients

• Presents with back pain followed by weakness.

• Sensory findings are absent

• Deep tendon reflexes are diminished on the affected side.

• Bowel and bladder function are not affected

HIV-Associated Peripheral Neurologic Disease

• CMV radiculitis-may be seen in the latter stages of AIDS-Acutely weak-Primarily lower extremity involvement-Varying degrees of bowel and bladder dysfunction-Hyporeflexia and decreased sensation-Rectal tone may be impaired

CMV Radiculitis

• Management-lumbar puncture reveals pleocytosis and increased protein-MRI of lumbarosacral spine demonstrates swelling and clumping

of cauda equina-IV gancyclovir started at 5mg/kg q 12

h X 14 d

Questions

• Which of the following includes bulbar muscle weakness, absent pupillary reflex, and proximal muscle weakness

a. polyomyositisb. botulism

c. Guillain-Barred. Lyme disease

Questions

• All of the following are associated with Lyme disease except

a. Tick Exposure b. Seventh nerve pulsy

c. Arthralgias and fatigued. abnormal mentantion

e. treatment with rocephin or doxycycline.

Answers: b, f, t, d

Questions

• In Guillain-Barre Syndrome, deep tendon reflexes are intact T/F

• Myalgias, proximal and bulbar muscle weakness, facial edema and eosinophilia are associated with Trichinosis T/F