Causes of Coma Classification

What are the two main classifications of the causes of coma mentioned in the text?

Which respiratory pattern is usually associated with irregular breathing in coma patients?

What may mimic coma according to the text?

In coma patients, what is the typical status of pupillary size and reaction?

What can cause unequal or unreactive pupils to light, with fixed midposition?

Which type of rigidity implies a destructive lesion of the corticospinal tracts within or very near the cerebral hemispheres?

In the context of brain damage, which condition involves a hemiplegia that is flaccid early in its course?

What does decerebrate rigidity typically involve?

What does dilated, fixed pupils suggest in the context of anticholinergics or hypothermia?

Which condition is characterized by the arms flexed tight to the sides with internally rotated legs?

What might cause decerebrate rigidity?

What type of response is seen in decerebrate rigidity?

Which condition involves sudden unilateral brain damage producing a hemiplegia that is flaccid early in its course?

What is suggested by unequal or unreactive pupils with fixed midposition?

Causes of Coma

There are two main classifications of the causes of coma: structural and metabolic

Respiratory Patterns in Coma

Cheyne-Stokes respiration is usually associated with irregular breathing in coma patients

Differential Diagnosis of Coma

Psychogenic unresponsiveness, catatonia, and Locked-In syndrome may mimic coma

Neurological Examination in Coma

The typical status of pupillary size and reaction in coma patients is unequal or unreactive pupils with fixed midposition

Pupillary Abnormalities

Unequal or unreactive pupils to light, with fixed midposition can be caused by midbrain damage or anticholinergics

Types of Rigidity

Decorticate rigidity implies a destructive lesion of the corticospinal tracts within or very near the cerebral hemispheres
Decerebrate rigidity typically involves extension of all four limbs and arching of the back

Neurological Conditions

Spastic hemiplegia involves a hemiplegia that is spastic late in its course, whereas flaccid hemiplegia involves a hemiplegia that is flaccid early in its course
Middle cerebral artery syndrome involves sudden unilateral brain damage producing a hemiplegia that is flaccid early in its course

Decerebrate Rigidity

Decerebrate rigidity may be caused by a destructive lesion in the rostral pons or midbrain
Decerebrate rigidity typically involves an extensor response to stimuli

Ocular Signs

Dilated, fixed pupils suggest anticholinergics or hypothermia
Unequal or unreactive pupils with fixed midposition suggest midbrain damage

Test your knowledge of the causes of coma by classifying them as either structural or metabolic. Understand the general guidelines for diagnosing coma and recognize how psychiatric disorders may mimic coma.