Syndromes Presenting As Acute Flaccid Paralysis

Syndromes Presenting as Acute Flaccid Paralysis Flaccid paralysis evolving over hours or a few days suggests involvement of the lower motor neuron complex (see section on Floppy Infant Syndrome). Anterior horn cells (spinal cord) may be involved by viral infection (paralytic poliomyelitis) or by paraviral or postviral immunologically mediated disease (acute transverse myelitis). The nerve trunks (polyneuritis) may be diseased as in Guillain-Barré syndrome or affected by toxins (diphtheria or porphyria). The neuromuscular junction may be blocked by tick toxin or botulinum toxin. The paralysis rarely will be due to metabolic (periodic paralysis) or inflammatory muscle disease (myositis). A lesion compressing the spinal cord must be ruled out. Clinical Findings Symptoms and Signs Features assisting diagnosis are age, a history of preceding or waning illness, the presence (at time of paralysis) of fever, rapidity of progression, cranial nerve findings, and sensory findings (Table 23–25). The examination may show long tract findings (pyramidal tract), causing increased reflexes and a positive Babinski sign. The spinothalamic tract may be interrupted, causing loss of pain and temperature. Back pain, even tenderness to percussion, may occur, as well as bowel and bladder incontinence. Often the paralysis is ascending, symmetric, and painful (muscle tenderness or myalgia). Laboratory findings occasionally are diagnostic. Table 23–25. Acute Flaccid Paralysis in Children.

Poliomyelitis (Paralytic, Landry-Guillain-Barré Spinal, and Bulbar), With Syndrome ("Acute Idiopathic or Without Encephalitis Polyneuritis")

Botulism

Tick-Bite Paralysis

Transverse Myelitis and Neuromyelitis Optica

Etiology

Poliovirus types I, II, and III; other enteroviruses, eg, EV71; vaccine strain polio virus (rare); West Nile virus: epidemic in birds. Mosquitoes infect horses, humans

Likely delayed hypersensitivity— with T-cell–mediated antiganglioside antibodies. Mycoplasmal and viral infections (EBV, CMV), Campylobacter jejuni, Hepatitis B.

Clostridium botulinum toxin. Block at neuromuscular junction. Under age 1, toxin synthesized in bowel by organisms in ingested dust or honey. At older ages toxin ingested in food. Rarely from wound infection.

Probable interference with transmission of nerve impulse caused by toxin in tick saliva.

Usually unknown; multiple viruses (herpes, EBV, varicella, hepatitis A) often postviral (see Guillain– Barré syndrome).

History

None, or inadequate polio immunization. Upper respiratory or gastrointestinal symptoms followed by brief respite. Bulbar paralysis more frequent after tonsillectomy. Often in epidemics, in summer and early fall.

Nonspecific respiratory or gastrointestinal symptoms in preceding 5–14 d common. Any season, though slightly lower incidence in summer.

Infancy: dusty environment (eg, construction area), honey. Older: food poisoning. Multiple cases hours to days after ingesting contaminated food.

Exposure to ticks (dog tick in eastern United States; wood ticks). Irritability 12–24 h before onset of a rapidly progressive ascending paralysis.

Rarely symptoms compatible with multiple sclerosis or optic neuritis. Progression from onset to paraplegia often rapid, usually without a history of bacterial infection.

Presenting complaints

Febrile at time of paralysis. Meningeal signs, muscle tenderness, and spasm. Asymmetrical weakness widespread or segmental (cervical, thoracic, lumbar). Bulbar symptoms early or before extremity weakness; anxiety; delirium.

Symmetrical weakness of lower extremities, which may ascend rapidly to arms, trunk, and face. Verbal child may complain of paresthesias. Fever uncommon. Facial weakness early. MillerFisher variant presents as ataxia and ophthalmoplegia (rare).

Infancy: constipation, poor suck and cry. "Floppy." Apnea. Lethargy. Choking (cause of SIDS?). Older: blurred vision, diplopia, ptosis, choking, weakness.

Rapid onset and progression of ascending flaccid paralysis; often accompanied by pain and paresthesias. Paralysis of upper extremities second day after onset. Sometimes acute ataxia presentation.

Root and back pain in about one-third to one-half of cases. Sensory loss below level of lesion accompanying rapidly developing paralysis. Sphincter difficulties common. Fever (58%).

Findings

Flaccid weakness, usually asymmetrical. Cord level: Lumbar: legs, lower abdomen. Cervical: shoulder, arm, neck, diaphragm. Bulbar:

Flaccid weakness, symmetric, usually greater proximally, but may be more distal or equal in distribution. Rarely cranial nerves IX–XI, III–VI. Miller-Fisher variant: ophthalmoplegia, ataxia.

Infants: Flaccid weakness. Alert. Eye, pupil, facial weakness. Deep tendon reflexes decreased. Absent suck, gag. Constipation. Older: paralysis

Flaccid, symmetric paralysis. Cranial nerve and bulbar (respiratory) paralysis, ataxia, sphincter disturbances, and sensory deficits may

Paraplegia with areflexia below level of lesion early; later, may have hyperreflexia. Sensory loss below and hyperesthesia or normal sensation above

CMV, cytomegalovirus; CSF, cerebrospinal fluid; EBV, Ebstein–Barr virus; IVIg, intravenous immune globulin; MRI, magnetic resonance imaging; PMN, polymorphonuclear neutrophil; SIDS, sudden infant death syndrome. Laboratory Findings (See Table 23–25.) Examination of CSF is helpful. Imaging studies of the spinal column (plain radiographs) and spinal cord (MRI) are occasionally essential. Viral cultures (CSF, throat, and stool) and titers aid in diagnosing poliomyelitis. A high sedimentation rate may suggest tumor or abscess; the presence of antinuclear antibody may suggest lupus arteritis. EMG and nerve conduction velocity can be helpful in diagnosing polyneuropathy. Nerve conduction is usually slowed after 7–10 days. Findings in botulism and tick-bite paralysis can be specific and diagnostic. Rarely, elevation of muscle enzymes or even myoglobinuria may aid in diagnosis of myopathic paralysis. Porphyrin urine studies and heavy-metal assays (arsenic, thallium, and lead) can reveal those rare toxic causes of polyneuropathic paralysis. Differential Diagnosis The child who has been well and becomes paralyzed often has polyneuritis. Acute transverse myelitis sometimes occurs in an afebrile child. The child who is ill and febrile at the time of paralysis often has acute transverse myelitis or poliomyelitis. Acute epidural spinal cord abscess (or other compressive lesion) must be ruled out. Poliomyelitis is very rare in our immunized population. Enterovirus 71 and West Nile disease are two new causes. Paralysis due to tick bites occurs seasonally (spring and summer). The tick is usually found in the occipital hair. Removal is curative. Paralysis due to botulinum toxin occurs most commonly in those younger than age 1 year (see Chapter 38). Intravenous drug abuse can lead to myelitis and paralysis. Furthermore, chronic myelopathy occurs with two human immunodeficiency virus infections: HTLV-I and HTLV-III (now called HIV-1). Complications Respiratory Paralysis Early and careful attention to oxygenation is essential. Administration of oxygen, intubation, mechanical respiratory assistance, and careful suctioning of secretions may be required. Increasing anxiety and a rise in diastolic and systolic blood pressures are early signs of hypoxia. Cyanosis is a late sign. Deteriorating spirometric findings (forced expiratory volume in 1 second and total vital capacity) may indicate the need for controlled intubation and respiratory support. Blood gases (usually late changes with increased CO2 and decreased O2) can aid decisions. Infections

Pneumonia is common, especially in patients with respiratory paralysis. Antibiotic therapy is best guided by results of cultures. Bladder infections occur when an indwelling catheter is required because of bladder paralysis. Recovery from myelitis may be delayed by urinary tract infection. Autonomic Crisis This may be a cause of death in Guillain-Barré syndrome. Strict attention to vital signs to detect and treat hypotension or hypertension and cardiac arrhythmias in an intensive care setting is advisable, at least early in the course and in severely ill patients. Treatment Most of these syndromes have no specific treatment. Ticks causing paralysis must be removed. Other therapies include the use of erythromycin in Mycoplasma infections and botulism immune globulin in infant botulism. Recognized associated disorders (eg, endocrine, neoplastic, or toxic) should be treated by appropriate means. Supportive care also involves pulmonary toilet, adequate fluids and nutrition, bladder and bowel care, prevention of decubitus ulcers, and in many cases, psychiatric support. Corticosteroids These agents are believed by most to be of no benefit in Guillain-Barré syndrome. Autonomic symptoms (eg, hypertension) in polyneuritis may require treatment. Plasmapheresis, Intravenous Immunoglobulin Plasma exchange or intravenous IgG has been beneficial in moderate or severe cases of Guillain-Barré syndrome. Some clinicians use inability to ambulate as a criterion to use IVIg. Physical Therapy Rehabilitative measures are best instituted when acute symptoms have subsided and the patient is stable. Antibiotics Appropriate antibiotics and drainage are required for epidural abscess.