Medicine 5th year, 2nd lecture (Dr. Hassan Al-Jumaily)
PERIPHERAL NEUROPATHY<br />(GUILLAIN-BARRÈ SYNDROME)<br />Peripheral neuropathy can be classified into the following:<br /><ul><li>Mononeuropathy simplex: means involvement of a single peripheral nerve.
Mononeuropathy multiplex: means involvement of more than one nerve (several nerves) at a random distribution.
Polyneuropathy: means involvement of numerous peripheral nerves at the same time, as in Guillain-Barre syndrome. </li></ul>Guillain-Barre syndrome: ‘acute idiopathic polyneuropathy’, it is also called acute ascending radiculopathy, it is an acute or subacute polyneuropathy predominantly affects nerve roots and nerve trunks that can follow minor infection, inoculation or surgical procedures, or may occur without any obvious precipitant.<br />Pathologically: there is a segmental demyelination of peripheral nerves, suspected to be due to an autoimmune mechanism (antibody and cell-mediated immunity) affected the myeline sheath of the peripheral nerves.<br />Clinical Picture:-<br />This disease occurs in all parts of the world and in all season, it affects children and adults of both sexes. The characteristic ‘cardinal’ clinical picture is a rapidly progressive weakness from lower limbs upwards with hyporeflexia.<br />Weakness usually begins in the distal lower limbs and spreads upwards to the upper limbs for that it is called ‘ascending paralysis’ and may involve the pharynx ‘bulbar weakness’ causes swallowing difficulty and nasal speech and may involve facial nerves (bilateral facial weakness), or may involve the intercostals muscles and other respiratory muscles causing respiratory difficulty and there may be need for artificial respiration. Some patients complain from sensory symptoms in the form of distal numbness and paresthesia which rarely progresses or persists. Also patients may complain from autonomic impairment in the form of fluctuated orthostatic hypotension and hypertension or in the form of cardiac dysrhythmia or sphincter disturbance. Patients usually give a history of fever or surgical procedure or any other precipitant factor within 3 days to 2 weeks before this complain, the weakness and other symptoms continue to progress for 3 days to 4 weeks, then remain stable on such complain for 2 to 4 weeks then improvement or recovery continue for a week to 6 months.<br />On examination: motor weakness in the upper and lower limbs of the lower motor type with areflexia or hyporeflexia, and slight sensory impairment and cardiac dysrhythmia. <br />Guillain-Barre syndrome—Diagnosis:-<br /> This depends on characteristic clinical picture and laboratory investigations. The most important of them is CSF study. CSF shows characteristic increase in protein (up to 500 mg/dL) and normal cells called ‘albumin-cytological dissociation’. While EMG study shows marked decrease in conduction velocity due to demyelination especially after one week of illness.<br />Guillain-Barre syndrome—Treatment:-<br /><ul><li>Plasmapharesis is used in the first two weeks significantly shortens the clinical course and reduces morbidity and functional disability.
Patient should be admitted to the respiratory care unit for unpredictable respiratory dyspnea and patients may require tracheostomy and blood pressure and cardiac function should be monitored carefully
Other symptomatic treatment and physiotherapy is important </li></ul>Prognosis:-<br /> The symptoms and signs stop progression within about 4 weeks. The disease is self-limiting, and improvement occurs over weeks or months. About 70 to 75 percent of patients recover completely, 25 percent left with mild neurological deficits and 5 percent will die.<br />DIPHTHERIA<br />Diphtheria is an acute infectious disease caused by Corynebacterium diphtheria and affects the nervous system by secretion of exotoxin.<br />The involvement of the nervous system follows a ‘predictable’ pattern. It begins locally with palatal paralysis as nasal voice, regurgitation and dysphagia within first 5 to 12 days of the illness, after 2 to 3 weeks cilliary paralysis will occur as loss of accommodation and blurring of vision. After 5 to 8 weeks limbs weakness or paralysis will occur due to sensorimotor polyneuropathy.<br />The neuropathic symptoms progress for 1 to 2 weeks and if the patient does not die by respiratory paralysis or cardiac failure (cardiomyopathy), they will stabilize and then improve slowly and completely.<br />Treatment:- <br />There is no specific treatment for neurologic complications, but they believe that the administration of diphtheric antitoxins within the first 24 – 48 hours decreases the incidence and severity of the complications.<br /><ul><li>Erythromycin may be useful for infections
Physiotherapy is important</li></ul>BELL’S PALSY<br /> It is a facial weakness of lower motor nerve involvement outside the central nervous system without evidence of other neurologic diseases. It occurs more commonly in the pregnant and those with DM, the weakness is usually preceded or accompanied by pain around the ear on the same side. The weakness either comes abruptly or progresses over several hours or even a day. There may be associated impairment of taste, lacrimation or hyperacussis. The weakness may involve all the facial muscles (complete paralysis) or parts of them (incomplete paralysis). Clinical examination shows no other abnormality other than facial weakness. <br /> Most patients recover completely without treatment in several days or several months. Points of poor prognosis include: <br /><ul><li>Severe pain at the onset
Complete paralysis</li></ul>Treatment:-<br /><ul><li>Prednisolone 60 mg/day for 3 days then taper over the next 7 days