Neuroscience Clerkship

 

 

COMPLEX PARTIAL SEIZURES: BEHAVIORAL AND MOTOR MANIFESTATIONS

Often, the word “seizure” is used interchangeably with “convulsion.” Although this is valid for generalized, tonic clonic seizures, other seizure types are not associated with loss of consciousness, or any twitching or jerking activity. Most common among these are complex partial seizures (CPS).
 

CPS often originate from the temporal lobe (70-80%) or parts of the frontal lobe. The pathology in the temporal lobes of most of these patients shows mesial temporal sclerosis (see figure above).

These seizures are often characterized by an aura followed decreased responsiveness and awareness of self and the environment (altered consciousness, not loss of consciousness). The aura is often emotional, olfactory or gustatory (i.e., an odd feeling, or unpleasant smell or taste). During a CPS, the patient appears awake. There is no loss of muscle tone, no convulsions, tongue biting or urinary incontinence. Hence, this seizure type is difficult to recognize, especially for the non-neurologist.


Following the aura, a CPS often begins with a wide-eyed, motionless stare, dilated pupils, and behavioral arrest. Once of the important clues of a CPS is the presence of certain behavioral and motor manifestations, known as automatisms, that occur during the seizure. Automatisms can be described as involuntary, coordinated motor activity/movements or behavior occurring during the state of clouding of consciousness in the course of a CPS. Patients may continue their ongoing motor activity or react to their surroundings in a semipurposeful manner.

Verbal automatisms range from simple vocalizations, such as moaning, to more complex, comprehensible, stereotyped speech.

Motor automatisms are classified as simple or complex:

Simple motor automatisms

Oral automatisms (e.g., lip smacking, chewing, swallowing)

Manual automatisms (e.g., picking, fumbling, patting)

Complex motor automatisms

(elaborate, coordinated movements involving bilateral extremities; e.g., cycling movements of the legs and stereotyped swimming movements)