Constitute hypothesis for origin of supernumerary phantom limb (SPL) after stroke.

Single case description, review of literature and formulation of hypothesis.

A 59-year-old lady was evaluated for complaints of left-sided hemiparesis and extra limbs attached to her left shoulder for the past 7 months. Neuropsychological assessment revealed left hemineglect with SPL, and profile suggested bilateral frontal, right parietotemporal and basal ganglia involvement. Magnetic resonance imaging brain scan showed gliotic cavity secondary to the old haematoma in right putamen with white matter changes in the right frontoparietotemporal lobes.

The conceptual framework of body schema can be used to classify many of the neurological disorders of body representation. Generation of SPL comes under the subtype of pathology of updating among the disorders of body schema. The continuous updating allows the body schema to modulate perceptual processing of objects according to their position in space. Brain areas classified as parts of motor system can, under pathological conditions (haemorrhage), influence body perception. So, when she used to move her arm, the representation of the estimated position was not updated by the motor commands. Sensory and motor information therefore becomes discrepant, and failure to integrate these two sources of information leads to loss of normal coherence, and the perceived shape of the body was altered by adding a SPL to accommodate the discrepancy.

The occurrence of a seizure during electroconvulsive therapy (ECT) should be confirmed. Most clinicians use motor seizure monitoring alone and recent guidelines have not considered electroencephalogram (EEG) monitoring mandatory.

To examine the potential pitfalls of motor seizure monitoring.

Consenting consecutive patients (n=232) were prospectively studied at the first ECT session using both motor and EEG seizure monitoring. It was ensured (by titration) that all the patients had an adequate EEG seizure. Adequate and prolonged seizures were defined according to the latest recommendations of the Royal College of Psychiatrists.

Motor seizure was inadequate in 15 (7%) of patients. EEG seizure was prolonged in 38 (16%) of patients. Fifteen patients (39%) did not have a prolonged motor seizure. Motor seizure correlated well (r=0.8, P < 0.001) with EEG seizure when the latter was adequate, but not when prolonged (r=0.12, P > 0.5).

Motor seizure monitoring without EEG is undependable. The study provides a rational basis for the Royal College of Psychiatrists' definition of prolonged EEG seizure.