A variety of disorders affecting the nervous system, not easily categorized otherwise, require management in the intensive care unit (ICU). These include the following:

A. Suicidal hanging.

B. Electrical injuries.

C. Carbon monoxide (CO) poisoning.

D. Decompression syndrome (“the bends”).

E. Cerebral fat embolism.

F. Hiccups.

G. Peripheral nerve disorders.

Second most common means of committing suicide among adolescents in the United States (US).

1. Death is usually by slow strangulation with compression of the jugular veins or carotid arteries.

2. Interruption of blood flow for more than a few minutes results in hypoxic-ischemic injury with neuronal death, cytotoxic/vasogenic edema, and increased intracranial pressure (ICP).

1. Poor prognostic signs.

a. Evidence of cardiopulmonary arrest, low Glasgow Coma Scale score.

b. Spontaneous respiratory rate of <4/minute, need for intubation.

c. Neurogenic pulmonary edema.

1. Cardiopulmonary resuscitation and treatment for cardiac arrhythmias.

2. Monitor for paratracheal/laryngeal trauma, or acute respiratory distress syndrome; endotracheal intubation can prevent airway obstruction.

3. Cervical spine should be stabilized until fracture is excluded or treated.

4. Treatment of increased ICP.

5. A carotid thrombus requires prompt vascular intervention.

In the US, there are 4,000 injuries and 1,000 deaths from electric shock annually.

1. Immediate effects.

a. Ten to fifty percent experience transient unconsciousness, headaches, or retrograde amnesia.

b. Brain hemorrhages occur with electrical injuries to the head. Spinal cord injuries are more common when electricity spreads from the ground to the patient.

c. Catecholamine release may result in autonomic dysfunction: diaphoresis, fixed dilated pupils, and keraunoparalysis (reversible limb paralysis accompanied by vasospastic vascular compromise following lightning injury).

2. Delayed effects.

a. Neuropsychiatric effects—for example, depression, memory impairment.

b. Reflex sympathetic dystrophy.

c. Myelopathies/motor neuronopathy.

1. Difficult to ascertain initially, since patients with deficits at presentation may recover fully, while those with delayed onset of neurologic deficits may have syndromes that linger for months.

1. Specific treatment for neurologic injuries secondary to electrical injuries not available.

2. Supportive medical/surgical care.

In physiologic amounts, endogenous CO functions as a neurotransmitter. Atmospheric CO concentration is normally <0.001%; concentrations of 0.1% can be fatal.

1. CO’s affinity for hemoglobin is more than 200 times that of oxygen, resulting in the formation of carboxyhemoglobin with even relatively low amounts of inhaled CO.

2. Clinical effects depend on the carboxyhemoglobin level and duration of exposure.

a. Mild exposures result in headache, myalgia, dizziness, or neuropsychological impairment.

b. Severe exposures to CO result in confusion, loss of consciousness, or death.

1. One hundred percent oxygen by a tight-fitting nonrebreathing face mask.

2. One hundred percent oxygen shortens half-life of CO from 4 to 5 hours to approximately 1 hour.

3. Hyperbaric oxygen therapy may be useful but remains controversial.

1. Approximately 75% recover within a year of the insult.

2. Approximately 10% to 30% develop memory impairment or extrapyramidal signs reminiscent of parkinsonism. Basal ganglia and substantia nigra neurons are highly sensitive to CO exposure.