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Some error has occurred while processing your request. All have similar clinical manifestations, but the mechanism of each is unique. Clostridium botulinum is an anaerobic, spore-forming bacterium. The toxin is taken up presynaptically in the cholinergic nerve endings by endocytosis and prevents the fusion of the synaptic vesicles with the nerve terminus. This prevents the release of acetylcholine presynaptically, which disrupts neurotransmission. Food-borne Botulism. Reports are clustered in the western states, particularly Alaska, where improper canning techniques or failure to prepare home-canned food properly are blamed.
In the summer of , four cases of food-borne botulism were reported. Each of those four cases presented to different emergency departments. Wound Botulism. This is the rarest of the three entities. Most cases in the United States are associated with injection drug use, more specifically the use of black tar heroin.
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Infantile Botulism. This is the most common form of botulism. Food-borne and wound botulism have indistinguishable symptomatology. The incubation period for food-borne botulism is hours. Cranial nerve deficits are the most common initial presentation. Common findings are diplopia, facial weakness, ptosis, dysphagia, and speech changes. The paresis and subsequent paralysis then descends to involve the upper extremities, then the lower extremities.
Respiratory muscle paralysis ensues as the process descends. The autonomic nervous system is affected, which results in dry mouth, postural hypotension, paralytic ileus, and pupillary abnormalities.
In all three varieties of botulism, the diagnosis is clinical. Stool and blood should be obtained for culture and toxin identification. Wounds may be cultured. However these are of no help in the primary care diagnosis and management of the condition. Routine diagnostic studies are only helpful to rule-out other conditions. In one emergency department case series of 29 patients with food-borne botulism, all patients had at least three of the following: weakness, dry mouth, double vision, and difficulty speaking.
Infant Botulism. Infant botulism presents after hours to days mean of 4. These symptoms are initially very subtle. Symptoms progress to poor head control and diffuse hypotonia "floppy baby". All suspected cases of botulism should be admitted to the ICU for observation and supportive care. If the patient's respiratory function is in peril, he or she should be immediately intubated and maintained on mechanical ventilation until the toxin's effects have abated, which can take weeks. Because the toxin binds irreversibly, patients will recover as they regenerate neuromuscular connections at their synapses.
In addition to supportive care, all patients should be treated with botulism antitoxin. The antitoxin has been shown to decrease mortality and reduce hospitalization. It prevents progression of the process but does not reverse the paralysis. The antitoxin can be obtained through state and local health departments and the CDC. These patients should also receive the equine derived antitoxin and should be treated supportively. The wound should be debrided. Antibiotics should be given for coexisting infection, but no studies have shown that their administration hastens recovery from the paralysis.
Supportive care is the primary treatment from the primary care perspective. Antibiotics are ineffective. Tick Paralysis. Because it is not reportable in all 50 states, it is difficult to ascertain its incidence. The condition occurs most frequently in the western United States and Canada, although it has been reported worldwide.
From , 6 cases were reported in the state of Washington. Children are classically the only victims of tick paralysis as the toxin is thought to be diluted in an adult's larger blood volume. Tick paralysis occurs when an adult female tick attaches to its victim. The tick passes the toxin on to the victim through its saliva while feeding. Symptoms develop within days after the tick attaches. Paraesthesias and ataxia are usually noted first. Then, weakness starts with the legs and spreads cranially. Loss of deep tendon reflexes and respiratory drive eventually occur. Patients are usually alert, although they may appear lethargic because of their muscular weakness.
Fever is uncommon. A progressive ascending weakness that appears similar to GBS is noted. One difference with tick paralysis is that there is commonly an associated ataxia that is not seen with GBS. Patients will complain of paresthesias but generally will not have sensory deficits on examination. Hyporeflexia to areflexia will occur in the similar distribution as the ascending motor weakness.
The primary diagnostic evaluation is a thorough physical examination, especially looking in the hair for the tick. No child should be diagnosed with GBS without thoroughly examining him or her for ticks generally in the scalp, axillae, and perineum. Removal of the tick results in rapid recovery. To remove the tick, grasp as close to the patient's skin as possible with a forceps and pull firmly. In Australia, the I. Holocyclus anti-toxin should be given prior to removal of the tick, as symptoms often worsen initially.
Carpal Tunnel Syndrome. Carpal tunnel syndrome CTS is the most common of the entrapment neuropathies. While most cases of CTS are idiopathic, up to one-third of cases are associated with coexisting states such as pregnancy, hypothyroidism, diabetes, renal failure, acromegaly, and steroid use.
CTS results from compression of the median nerve as it passes through the carpal tunnel created by the rigid carpal bones, nine flexor tendons, and the transverse carpal ligament. The earliest manifestations of CTS are pain, paresthesias, burning, or numbness in the distribution of the median nerve, which involves the volar aspects of the thumb, index, and middle finger in addition to the radial one-half of the ring finger.
Patients frequently report shaking their hand when the pain is present. Symptoms can be bilateral, but the dominant hand is usually affected more severely. While sensory symptoms predominate, the patient may develop weakness of thumb abduction and later develop atrophy of the thenar eminence. Sensory complaints, such as numbness and tingling, are the most common complaints with CTS. Sensory deficits to light touch and two-point discrimination occur over the distribution of the median nerve as described previously.
Diagnostic Testing. There is no diagnostic test that is specific or sensitive for CTS. Tinel's sign involves tapping over the volar surface of the wrist to see if it causes paresthesias in the digits in the median nerve distribution. A positive result is the creation of pain or paresthesia in the median nerve distribution. Treat the patient with a neutral wrist splint. This has been shown to be effective in mild cases, and is the least invasive treatment option. While nonsteroidal anti-inflammatory drugs commonly are prescribed, most studies have shown them to be ineffective.
Steroids have been shown to be effective in the short term, 41 but surgery is the definitive treatment in refractory cases. Ulnar Neuropathy at the Elbow. Ulnar neuropathy at the elbow is the second most common entrapment neuropathy of the upper extremity. There are many potential areas around the elbow that can cause the ulnar nerve entrapment or neuropathy.
In general, the ulnar neuropathy occurs as a result of either external compression, entrapment in the cubital tunnel or at the flexor carpi ulnaris, or by acute or chronic traction injury. Patients complain of elbow pain that radiates down the ulnar portion of the forearm, hand weakness, and numbness or paresthesias in the ulnar side of the hand and the ring and small fingers. Patients who tend to sleep in the fetal position will notice nocturnal symptoms as well.
Similar to CTS, motor involvement is less common or appears later in the disease process. Patients may have a reduced grip strength associated with atrophy of the interosseous or hypothenar muscles. Weakness of the first dorsal interosseous and flexor carpi ulnaris are the more common findings.
Finally, weakness of flexor digitorum profundus of the small and ring fingers occurs later. Decreased sensation of the small finger and the ulnar half of the ring finger, ulnar palm, and dorsum of the hand is present. Electrodiagnostic testing is the primary way to confirm the diagnosis.
Provocative maneuvers that may help in the diagnosis include tapping over the nerve in the ulnar groove for reproduction of paresthesias. Also, sustained elbow flexion, possibly with manual pressure over the ulnar groove may also reproduce the symptoms. Management of ulnar neuropathy at the elbow should be conservative. Patients should be educated to avoid activities associated with repetitive or sustained elbow flexion and to avoid putting pressure on the elbow.
Surgery is considered as a last resort in severe lesions or in those who fail to respond to conservative management. Compressive Radial Neuropathy. Compressive radial neuropathy CRN , commonly referred to as "Saturday Night Palsy," is caused by compression of the radial nerve as it passes through the spiral groove of the humerus. This condition gets its name because it classically occurs when an intoxicated person falls asleep with his or her arm draped over a chair or bench, compressing the nerve. It is less common than median or ulnar nerve compression.
Prolonged compression of the nerve leads to demyelination and, in severe cases, axonal degradation. Sensory loss may also occur on the lateral portion of the dorsal hand and the dorsal aspect of the first four fingers. The predominant result of CRN is weakness of the wrist and finger extensors, which results in a wrist drop. The triceps has normal strength because its innervations occur proximal to the radial groove. Decreased sensation over the radial portion of the dorsum of the hand and the dorsal aspects of the thumb through the ring finger.
There will be diminution of the brachioradialis reflex but a normal triceps reflex. Electrodiagnostic testing is the primary way to confirm the diagnosis and to render a prognosis for recovery. CRN is almost always treated conservatively. Symptoms usually resolve spontaneously within a few days or weeks. However, in severe cases where axonal damage has occurred, symptoms can last for more than a year. In patients with significant wrist or finger drop, a cock-up wrist splint can help keep them in extension. There will be situations when the patient presents with a definite peripheral neuropathy on history and examination but it does not fit any well described disorder.
In those cases the physician needs to broaden the differential diagnosis and consider toxin-induced peripheral neuropathy.
Neuromuscular disorders in clinical practice
Toxins that should be considered include the following: arsenic, colchicine, dapsone, ethanol, lead, lithium, mercury, organophosphate pesticides, phenytoin, thallium, toluene, and L-tryptophan. When there is a suspicion of a toxin-induced neuropathy the case should be discussed with a toxicologist who has the skills, knowledge, and expertise to best determine the next step for the patient. There are several life-threatening and benign neuromuscular disorders and peripheral neuropathies that will be encountered. A focused history and structured neurological examination of the patient concentrating on the strength, sensation, and reflexes as well as a search for autonomic dysfunction will allow the physician to narrow the differential diagnosis.
Am Fam Physician ; Tsang RS. Curr Opin Infect Dis ; Pascuzzi RM. Peripheral neuropathies in clinical practice. Med Clin North Am ; Ayyar R. Clinical presentations of peripheral neuropathies. Neuroimaging Clin N Am ;, vii. Curr Opin Neurol ; Ann Emerg Med ; Crit Care Med ; Neurology ; Disorders of neuromuscular junction ion channels. Am J Med ; Myasthenia gravis: Diagnostic and management dilemmas.
Curr Opin Neurol ; Asystole induced by edrophonium following beta blockade. Neurology ; Lambert-Eaton myasthenic syndrome: Electrodiagnostic findings and response to treatment. Neuromuscular disorders in clinical practice: Case studies.
Neurol Clin ; Long term outcome in Lambert-Eaton myasthenic syndrome without lung cancer. J Neurol Neurosurg Psychiatry ; Custodio CM. Neuromuscular complications of cancer and cancer treatments. Peripheral nervous system involvement in patients with cancer. Lancet Neurol ;6: Autonomic dysfunction in the Lambert-Eaton myasthenic syndrome: Serologic and clinical correlates.
Botulism: Emergency Preparedness and Response. Food poisoning. Emerg Med Clin North Am ;; abstract ix. Wound botulism associated with black tar heroin among injecting drug users.
JAMA ; Infant botulism: A review of 12 years' experience at the Children's Hospital of Philadelphia. Pediatrics ; Emergency department presentation of type A botulism.
Am J Emerg Med ; Human botulism immune globulin for the treatment of infant botulism. N Engl J Med ; From the Centers for Disease Control and Prevention. A six-year-old girl with tick paralysis. Tick paralysis in the United States: A photographic review. Arch Neurol ; The rational clinical examination. Does this patient have carpal tunnel syndrome? JAMA ; Clinical practice. Carpal tunnel syndrome. Nerves in a pinch: Imaging of nerve compression syndromes.
Radiol Clin North Am ; Entrapment and compressive neuropathies. Med Clin North Am ;, viii. Goodyear-Smith F, Arroll B. What can family physicians offer patients with carpal tunnel syndrome other than surgery? A systematic review of nonsurgical management. Ann Fam Med ; Injection with methylprednisolone proximal to the carpal tunnel: Randomised double blind trial. BMJ ; A randomized controlled trial of surgery vs steroid injection for carpal tunnel syndrome. Ulnar neuropathy at the elbow.
Neurol Clin ;, v-vi. Corwin HM.