Vestibular testing in comatose patients

The analysis of vestibular responses in a comatose patient often provides the critical information for making a correct preliminary diagnosis and directing the subsequent laboratory evaluation. Because of some uncertainties about what is being tested with the various bedside maneuvers that are used to elicit vestibular responses, we review the physiologic basis for the oculomotor responses that occur with head rotation or with caloric stimuli. We further urge precise and unambiguous terminology to describe both stimulus and response. We suggest using physiologically well-defined terms such as vestibulo-ocular reflex and cervico-ocular reflex and avoiding potentially misleading terms such as the doll's head and the oculocephalic maneuvers.     

Craniopharyngioma of the cranial base and nasopharynx

A rare case of craniopharyngioma extending to the cranial base and nasopharynx is reported and eight other cases in the literature are reviewed. The embryology and the clinical features of these tumors are discussed. Tomograms of the skull and computed tomography are the most useful radiological tools of investigation. A nasoseptal or transpalatal approach to surgery, which has been performed in reported cases of cystic nasopharyngeal craniopharyngiomas, was not performed on our patient because of the hard consistency and the diffusely infiltrating aspect of the tumor.     

Lesser metatarsophalangeal joint implants

A double-stemmed MTP joint silastic implant has been described that acts as a flexible spacer for a number of pathologic conditions that affect the lesser metatarsophalangeal joints. Preliminary results suggest that this is a feasible alternative to joint destructive procedures with advantages over previously described implants.     

Clonidine in the treatment of Tourette's syndrome exacerbation due to haloperidol withdrawal

A patient with long-standing Tourette's syndrome had a dramatic exacerbation of symptoms following the rapid withdrawal of haloperidol. Clonidine administration resulted in a disappearance of tics, which recurred 6 days later. The role of clonidine in blocking withdrawal-induced symptoms in patients with Tourette's syndrome treated with long-term neuroleptics is discussed from a clinical and neurobiological perspective. The implications of this case for the treatment of supersensitivity psychosis and tricyclic withdrawal states with clonidine are also discussed.     

Asymptomatic oligoclonal CSF IgG and progressive increase of intrathecal IgG synthesis in a patient with myasthenia gravis treated with thymectomy--a 4-years follow-up

A young woman is described who had myasthenia gravis which was favourably influenced by thymectomy. Although there was no evidence for another neurological disease over 7.5 years of clinical observation and computed tomography as well as visual evoked response were normal, CSF studies over 0.5 years prior to and 3.5 years after thymectomy revealed persistent mononuclear pleocytosis, high CSF IgG index, oligoclonal IgG bands in CSF, and increasing IgG synthesis rate within the CNS, reflecting a continuous local humoral immune response. CSF/serum ratios of antibodies to acetylcholine receptors (AChR) were continuously lower than CSF/serum IgG ratios, contradicting intrathecal AChR antibody production. Proportion of total T cells was slightly higher in CSF than peripheral blood, while active T cells were lower in CSF. CSF lymphocytes did not proliferate on PHA stimulation but responded in allogeneic mixed lymphocyte culture. B cells were 4% in CSF and 4.5% in peripheral blood, but 227 IgG, 0 IgA and 0 IgM producing cells were detected among 20 X 10(3) CSF lymphocytes, compared to 5, 4 and 0 in 20 X 10(3) peripheral blood lymphocytes. This patient represents an in vivo 'experiment' regarding influence of thymectomy on CSF compartment constituents. The present study also shows that an individual can be clinically healthy despite continuous and pronounced intrathecal immune response.     

Effectiveness and nutritional consequences of amino acid-based vs glucose-based dialysis solutions in infants and children receiving CAPD

Excessive glucose absorption and dialysate amino acid and protein losses contribute to malnutrition in children on glucose-based continuous ambulatory peritoneal dialysis (CAPD). We used 2.5 and 4.25% glucose and 1.1 and 2.0% amino acid dialysates to assess short-term effectiveness and nutritional consequences of amino acid-based dialysis solutions. Plasma and effluent urea and creatinine concentrations were similar with amino acid and glucose dialysis although 16% less fluid was removed with amino acid dialysates. Absorption of 77.3 +/- 5.3% of dialysate amino acids exceeded losses of amino acids and protein in glucose effluent. With amino acid dialysates, fasting plasma glucose concentrations were maintained while plasma amino acid levels rose, peaked at 1 h, and, excepting methionine, isoleucine, and phenylalanine with the 2.0% solution, returned to initial levels after 5 h. Compared with glucose, amino acid dialysates provide reduced but satisfactory fluid and waste removal, maintain normoglycemia, and more than compensate for effluent losses of amino acids and protein.     

Gamma-aminobutyric acid receptors in the central nervous system of mammals

The review describes properties of gamma-aminobutyric acid (GABA) receptors in the central nervous system of mammalians. Two pharmacologically different receptors--GABAA and GABAB--are involved into GABA-ergic inhibition. GABA receptors (bicuculline-sensitive) regulate chloride permeability of membranes and can be functionally enhanced by benzodiazepine and barbiturate. GABA receptors (bicuculline-insensitive) are suggested to regulate calcium permeability.