Neurological/Neuromuscular

Meningitis• An infection of the meninges

• Causes• Bacterial

• Community acquired: pneumococcus/meningococcus, hemophilus

• Hospital acquired: staphylococcus, gram- rods

• Viral• Coxsackie, mumps, mycobacterium TB,

leptospirosis

• Liseria and crytococcus more common in immunosuppressed patients

Meningitis • Clinical features

• Fever• Nausea/vomiting• Sepsis• Malaise • Diarrhea• Endocarditis• Headache• Neck stiffness• Pneumonia • Photophobia

Meningitis • Investigation

• Lumbar puncture• Blood cultures

• Treatment• For bacterial, use ATB• Steroids can reduce complications• Rifampin given to those in close contact for

meningococcal and hemophilus

Encephalitis • An acute, usually viral, brain infection• A rare complication of common viral

diseases like chickenpox and mumps• Clinical features: drowsiness, irritability,

fever, neurological signs• Severe cases progress to sz, coma, death• CSF has elevated lymphocytes and protein• Management is mostly supportive• Antivirals (acyclovir/gancyclovir) may be

used

Other neurological infections• Tetanus

• Caused by Clostridium tetani• Enters body through a wound• Muscle rigidity, spasms, and respiratory failure• Requires heavy sedation/paralysis and

mechanical ventilation• Treated with immunoglobulin, ATB, and

surgical debridement of the infected wound

• Polio, botulism, and rabies also cause paralytic neurological infections

Guillain-Barre Syndrome• The most common cause of generalized flaccid

paralysis• Usually follows a flu-like illness, but can also

follow Epstein-Barr virus, CMV, HIV, hepatitis, campylobacter infections

• Causes a demyelinating neuropathy• Clinical features

• Starts with distal parasthesia• Ascending weakness/paralysis

• Prognosis• About 1/3 of GB patients require ventilation• Mortality is low (<10%) but about 10% of survivors

have residual effects

Myasthenia Gravis• An autoimmune disorder with muscle weakness• Acetylcholine receptors are attacked by

antibodies, reducing transmission of impulses to the muscles

• Thymus gland abnormalities are found in ~75% of cases

• Clinical features• Onset is slow and develops over weeks• Muscle weakness that increases with repetitive use• Eye muscles frequently involved• Ptosis and diplopia are most common presenting

features• Myasthenia crisis

• A life-threatening deterioration of MG caused by infection, fever, surgery, or drugs…leads to rapid respiratory failure

Myasthenia Gravis• Investigation

• Check blood for Ach receptor antibodies• EMG – shows decline in muscle fx• Tensilon test

• Tensilon prevents breakdown of Ach• Increased Ach levels will increase muscle fx• Improved strength after Tensilon administration is

diagnostic for MG

• Management• Follow VC/NIF• Check swallow• Thromboembolytic precautions

Myasthenia Gravis• Specific treatment

• Anticholinesterase drugs• Provide symptomatic relieve

• Pyridostigmine

• Can’t use Tensilon because it doesn’t last long

• Immunosuppressive drugs• Suppress antibody formation

• Steroids

• Plasma exchange• Produces short-lived (~1 month) improvement

• May be used to facilitate weaning

• Thymectomy• Improves ~80% of MG

Critical Illness Polyneuropathy• Occurs after sepsis, MOF, or high-dose

steroids (especially if combined with paralytics)

• Can cause degeneration of the motor and/or sensory nerves

• Leads to weakness, wasting, weaning failure, and loss of reflexes

• Treatment is symptomatic and recovery can be extended