Descriptive Psychopathology: The Signs and Symptoms of ...

188 Section 3: Examination domainsFigure 7.1 The signature of a patient with apraxic agraphianon-dominant alien hand may be experienced in conflict with the patient’s statedpurposes, the patient grabbing or slapping the alien (the “bad”) hand to preventan action, angrily shouting at the alien hand, and the alien hand attacking thesufferer. This uncommon delusion of alienation and control is most commonlyassociated with anterior brain lesions: the anterior corpus callosum, the mesialfrontal cortex contralateral to the alien hand, the supplementary motor area,anterior cingulated gyrus, and medial prefrontal cortex of the dominant cerebralhemisphere, or in the thalamus. 157Periodic paralysisPeriodic paralysis is a hereditary disorder (usually autosomal dominant) characterizedby episodic muscle weakness associated with abnormal potassium levels(hypo- and hyperkalemia) or sensitivity to changes in serum potassium. Attackslast minutes to days. They are triggered by exercise that is quickly followed bysustained rest, excitement, or cold temperature. Episodes typically begin in proximalmuscles spreading distally. After several years, permanent weakness occurs. 158Startle diseaseStartle disease, or recurrent exaggerated startle (a flexed crouch, blinking, andgrimacing), represents a group of conditions associated with many etiologies.Startle epilepsy is one form, mostly seen in children with other signs of neurologicdisease. Triggered by unexpected stimuli, the startle can progress to a generalizedor partial complex seizure. 159Stiff person syndromeStiff person syndrome is also elicited by sudden tactile or emotional stimuli orstartling noises. The sufferer suddenly develops painful spasms of the axialmuscles that become “board-like”. Spasms can last weeks, although brief spasms