MR imaging of brain-stem hypoplasia in horizontal gaze palsy with progressive scoliosis.

We present the MR imaging findings of a girl with horizontal gaze palsy and progressive scoliosis (HGPPS). HGPPS is a rare congenital disorder characterized by absence of conjugate horizontal eye movements and accompanied by progressive scoliosis developing in childhood and adolescence. MR imaging depicted brain-stem hypoplasia with absence of the facial colliculi, presence of a deep midline pontine cleft (split pons sign), and a butterfly configuration of the medulla. These MR imaging features suggest the diagnosis of HGPPS and correlate with the clinical findings. We hypothesize that maldevelopment of dorsomedial brain-stem structures plays a crucial role in the pathogenesis of HGPPS.

Impairment of the production of delta sleep in anorectic adolescents.

OBJECTIVE: Total sleep time and slow-wave sleep (SWS) are frequently reported to be reduced in anorectics. A preliminary study showed that slow-wave activity (SWA, 0.5-4.5 Hz) is decreased in anorectic adolescents. The present study investigates whether this reduction is the result of the increased sleep fragmentation or is dependent on an intrinsic weakness of SWA-producing mechanisms. DESIGN: Statistical analysis of spectral electroencephalogram data recorded during sleep from a group of anorectics and a control group. SETTING: Polysomnographic data were recorded in single rooms in the hospital for 1 night following an adaptation night. PARTICIPANTS: 20 adolescent anorectic girls (13.9 +/- 2.0 years) and 12 age-matched control subjects. INTERVENTIONS: Refeeding and psychotherapy. MEASUREMENTS AND RESULTS: Anorectics had an increase of wakefulness after sleep onset, a higher number of arousals, and a reduction of SWS and SWA during total sleep time. No relationship between the reduction of SWA and duration of illness was found, while a relationship between SWA decrease and the level of emaciation (body mass index) was present. The analysis limited to the first non-rapid eye movement sleep cycle did not show any difference between the 2 groups in the number of awakenings and arousals. Nevertheless, anorectics showed a reduction of SWS and SWA. CONCLUSIONS: Sleep of anorectic patients seems to be characterized by an impairment of SWA-producing mechanisms independent of the increased sleep fragmentation. This is probably related to the primary pathophysiologic characteristics of the illness but could also reflect secondary functional and anatomic alterations of the brain.