High-dose intravenous human immunoglobulin in chronic inflammatory demyelinating polyneuropathy.

We treated nine consecutive patients with chronic inflammatory demyelinating polyneuropathy (CIDP) with high-dose intravenous human immunoglobulin (HIG), and clinical recovery rapidly followed. Disability that had persisted for months or years was often reversed in days. There were no major adverse reactions to HIG infusions.

Expression of major histocompatibility complex antigens in neonate rat primary mixed glial cultures.

Primary mixed glial cultures containing astrocytes, oligodendrocytes and macrophages have been cultured from cerebral hemispheres of neonate rats and examined by indirect immunofluorescence for the expression of class I and II RT1 major histocompatibility complex-coded antigens. None of these cells expressed detectable levels of either class I or II antigens except for the macrophages which were weakly class I positive. Treatment with lymphokine-containing supernatant from concanavalin A-activated splenic lymphocytes resulted in increased expression of class I antigens on all cells together with the appearance of class II RT1.B and RT1.D antigens on macrophages and a small proportion of type 1/protoplasmic astrocytes. The identity of the Ia antigens was confirmed by immunoprecipitation from lysates of surface-iodinated cells. The ability of lymphokine-treated mixed glial cultures to stimulate proliferation of allogeneic lymphocytes provides additional evidence of Ia induction. A possible role for these Ia+, putative antigen-presenting cells in delayed type hypersensitivity in the central nervous system is discussed.

The phagocytes of neonate rat primary mixed glial cultures.

The phagocytes present in mechanically dissociated neonate rat cerebral hemispheres have been cultured and characterized both qualitatively and quantitatively. They comprise about 10% of the starting cell suspension and persist but do not proliferate in culture. They do not possess neuronal or neuroglial antigens but do express the leukocyte common antigen and readily ingest both latex beads and opsonized erythrocytes. the latter by an Fc receptor-mediated process. Evidence is presented that these cells are a bona fida component of the neonate central nervous system.

Vertigo and drop attacks caused by acute transient monocular disequilibrium (Halpern's syndrome).

Among the causes of acute vertigo the syndrome of sensorimotor induction in unilateral disequilibrium (Halpern's syndrome) should be considered. This syndrome was found in a patient and described in detail. The major features of this syndrome are the displacement of vertical and horizontal axes induced by looking with the "affected" eye only, which are further aggravated by applying red filters to the eyes only, which are further aggravated by applying red filters to the eyes and corrected by blue filters. The symptomatology is described and discussed in detail. Theories causing this syndrome are discussed.

The diagnostic accuracy of selected neurological tests.

The diagnostic value and reliability of selected neurological clinical tests was studied in control subjects with normal neuroimaging (n=42), and subjects with a focal brain lesion (n=38). The items were studied by two examiners blinded to group membership and using standardized protocols, and subsequently by a neurologist who was not blinded to diagnosis. The positive likelihood ratios ranged from 1.06 (pronator drift) to 22.11 (single leg stance with eyes open, while the negative likelihood ratios ranged from 0.47 (tandem gait) to 0.97 (pupil symmetry). Three items (single leg stance - eyes closed - firm surface; single leg stance - eyes open - foam surface; and tandem gait) successfully distinguished between the two groups (odds ratio p<0.05). The inter-rater reliability was generally poor, with only tandem gait showing excellent agreement (kappa [K]=0.92). Tandem gait was the only item to show noteworthy agreement (K=0.93) between the examiners and the neurologist. The tests varied considerably in their ability to detect radiologically demonstrated structural brain lesions, and several items were poorly reproducible, questioning their value as part of a routine neurological examination.

Reliability and diagnostic characteristics of clinical tests of upper limb motor function.

There is a paucity of information on the inter-rater reliability and predictive value of components of the neurological examination. Selected tests of upper limb motor function were studied in 34 patients with Parkinson's disease, upper motor neuron disease or cerebellar disease and in 25 control participants. Video recordings were independently evaluated and scored by two clinicians to determine inter-rater reliability (kappa) and predictive values. Kappa values ranged from 0.00 to 0.73. Highest positive predictive values (PPV) were obtained for the Barré test, arm raise, forearm rolling and finger nose tests. Negative predictive values (NPV) were mostly low, with highest values for unimanual sequential finger tap and rhythmic tap. The combined tests had PPV of 0.58 and NPV of 0.73. This study demonstrates that these clinical tests have poor inter-rater reliability and low negative predictive value when used in isolation.

Concussion causes transient dysfunction in cortical inhibitory networks but not the corpus callosum.

The corpus callosum (CC) is thought to be especially vulnerable in traumatic brain injury. Bimanual cost (a slowing of reaction time with bimanual compared to unimanual responses) is a sensitive indicator of CC function. To determine whether CC dysfunction is a significant feature of mild traumatic brain injury, unimanual and bimanual reaction times were studied in 10 recently concussed patients and 10 healthy participants. Reaction times were studied within 1 week of concussion and again after 1 month. Concussion symptoms were assessed with the Rivermead Postconcussion Symptoms Questionnaire. The bimanual cost was present at both testing sessions in patients and healthy controls. Although overall reaction times were slower in concussed patients during session 1, these had improved by session 2, as did the symptom scores. These findings suggest that the pathogenesis of mild traumatic brain injury involves intrahemispheric cortical networks rather than impaired interhemispheric communication via the CC.

Slow axonal transport is impaired by intrathecal 2,5-hexanedione.

Anterograde axonal transport was studied in a new model of hexacarbon neuropathy, in which neurofilament (NF)-containing giant axonal swellings are induced proximally in the spinal nerve roots of rats by intrathecal injection of 2,5-hexanedione (2,5-HD). Decreased transport velocity of the NF-containing slow component a (SCa) was demonstrated in 2,5-HD-treated animals, in contrast to studies demonstrating increased velocity of SCa in proximal parts of the axon in systemic 2,5-HD intoxication, which causes distal axonal swellings. Other components of anterograde transport were unaffected. In systemic 2,5-HD toxicity, velocity of NF transport increases in the proximal axon, but may decrease distally, where it is difficult to study. Decreased NF transport is likely to be responsible for the formation of axonal swellings, since they occur preterminally rather than at the axon terminal as would be expected if increased NF transport were the cause. Covalent modification of proteins provides a possible mechanism by which 2,5-HD affects axonal transport, and the effect may be facilitatory or inhibitory depending on the level and duration of exposure of the NF to the toxin.