Neurosensory assessments of migraine.

Headache medicine is primarily dependent on patients' subjective reports of pain, which are assessed at diagnosis and throughout the duration of treatment. There is a need for an objective, quantitative biological measurement of headache pain severity. In this study, quantitative sensory testing (QST) was conducted via multi-site vibrotactile stimulation in patients with migraine. The purpose was to investigate the sensitivity of the method and to determine if the metrics obtained from migraineurs could be differentiated from controls. Metrics reflecting sensory percepts of baseline measures of stimulus amplitude discrimination, temporal order judgment, and duration discrimination were significantly different. Additional measures previously demonstrated to be sensitive to alterations in centrally-mediated information processing features such as adaptation and synchronization were also significantly different from control values. In contrast, reaction times and vibrotactile detection thresholds of migraineurs failed to differentiate them from controls, indicating that the results are not due to peripheral neuropathy or some other primary afferent mechanism. The long-term objective of the study is to develop methods that can improve diagnosis and enable more accurate assessments of treatment efficacy in migraine.

Capture-recapture, epidemiology, and list mismatches: several lists.

In applying capture-recapture methods for closed populations to epidemiology, e.g., in the estimation of the size of a diabetes population, one comes up against the problem of list errors due to mistyping or misinformation. This problem has been studied for just two lists by Seber, Huakau, and Simmons (2000, Biometrics 56, 1227 1232) using the concept of tag loss borrowed from animal population studies. In this article, we discuss a similar method that can be extended to an arbitrary number of lists. The methods are applied to an example.

Idiopathic nodular glomerulosclerosis.

Idiopathic nodular glomerulosclerosis is an unusual entity with light microscopic and ultrastructural features similar to those of nodular diabetic glomerulosclerosis but without evidence of abnormal glucose metabolism. We report 2 patients whose renal biopsies showed nodular glomerulosclerosis with afferent and efferent arteriolosclerosis, glomerular basement membrane thickening, focal mesangiolysis and capillary microaneurysm formation, and who had no evidence of abnormal glucose metabolism or other features of diabetes mellitus. Review of the literature shows that, of the 27 reported cases of idiopathic nodular glomerulosclerosis (not including the 2 cases reported herein), 11 showed evidence of abnormal glucose metabolism or were frankly diabetic. Of the remaining 16 cases with normal serum blood glucose measurements, 3 had diabetic retinopathy and 1 had a delayed insulin response curve. The cause and pathogenesis of the glomerular nodules are discussed, and it is suggested that arteriolar stenosis and glomerular ischemia may be involved in the development these lesions.

Paroxysmal dyskinesias in patients with HIV infection.

OBJECTIVE: To determine the clinical features of paroxysmal dyskinesias among HIV type 1 (HIV-1)-seropositive patients. BACKGROUND: Movement disorders have been associated with HIV infection, although the full spectrum of these disorders remains uncertain. METHODS: Six adult HIV-1-seropositive patients presenting with paroxysmal dyskinesias were identified. Each patient underwent metabolic, CSF, EEG, and neuroimaging studies. RESULTS: Mean age at onset was 34.5 years and five of six patients were AIDS defined. Dyskinesias were focal, multifocal, or hemidystonic in four patients and generalized in another two patients. Two of the six patients had paroxysmal kinesigenic dyskinesias and the remaining four patients had paroxysmal nonkinesigenic dyskinesias. Choreoathetosis (n = 3), myoclonus (n = 2), postural tremor (n = 5), and dysarthria (n = 3) were observed. Benzodiazepines appeared beneficial in three of six patients. Two patients with HIV-associated dementia and paroxysmal nonkinesigenic dyskinesia had a progressive course to death. Autopsy of a patient with paroxysmal nonkinesigenic dyskinesias revealed intense astrogliosis and loss of calbindin-positive neurons in the subcortical gray matter. CONCLUSIONS: Paroxysmal dyskinesias may present as a primary HIV-1-induced neurologic syndrome. The occurrence of paroxysmal dyskinesias is associated with neuronal injury and loss in the subcortical gray matter but the mechanism remains unknown.

Thrombotic microangiopathy associated with cryoglobulinemic membranoproliferative glomerulonephritis and hepatitis C.

Cryoglobulinemic membranoproliferative glomerulonephritis (MPGN) and increased incidence of vascular thromboses are complications of hepatitis C virus (HCV) infection. This report describes the clinical, laboratory, and renal biopsy findings in two HCV-positive patients with cryoglobulinemic MPGN and thrombotic microangiopathy (TMA). Testing for circulating antiphospholipid antibodies, which are detected in a significant proportion of patients with HCV, was negative in the one case in which it was done. This article discusses the possible cause of the TMA in these two cases.

Colonic carcinoma in two adult cystic fibrosis patients.

Two adult women with cystic fibrosis (CF) who developed colonic carcinoma, both at age 31, are described. In both patients the carcinoma occurred in the midtransverse colon. The diagnosis had not been suspected, partly because of the patients' relatively young age. In case 1, the symptoms also mimicked the distal intestinal obstruction syndrome. At diagnosis she was shown to have metastases to the regional lymph nodes. In case 2, despite a long history of chronic pulmonary and sinus disorders, CF was not diagnosed until the patient was 36 years old. The incidence of gastrointestinal malignancies has been shown to be significantly increased in patients with CF. As the life expectancy of the CF population increases, vigilance for gastrointestinal cancers in CF patients is important, as illustrated by these two cases.

Multifocal necrotizing leukoencephalopathy with pontine predilection in immunosuppressed patients: a clinicopathologic review of 16 cases.

Multifocal necrotizing leukoencephalopathy (MNL) is characterized by multiple, usually microscopic, foci of necrosis confined primarily to the white matter of the basis pontis, but sometimes found elsewhere in the central nervous system. All 16 patients in whom we identified MNL had underlying immunosuppression, either naturally occurring or iatrogenic, including the acquired immunodeficiency syndrome (seven patients), acute leukemias (four patients), and lymphoma (one patient). One patient each had severe combined immunodeficiency, orthotopic liver transplantation, Shwachman-Diamond syndrome, and idiopathic thrombocytopenic purpura treated with high-dose steroids. Histologically, lesions of MNL show demyelination, spongiosis, axonal swelling, minimal histiocytic infiltrates, and frequent axonal calcification. Multifocal necrotizing leukoencephalopathy lesions were found in the pons of all patients, most commonly in the crossing pontocerebellar fibers, but often in the descending white matter tracts and rarely in the tegmentum. Three cases also showed nonpontine foci of MNL involving the white matter of the medulla, cerebellum, and cerebral hemispheres. Multifocal necrotizing leukoencephalopathy is a distinct entity usually localized to the basis pontis and is most consistently associated with immunosuppression, but as yet lacks other clearly defined clinical correlates.

Neuropathology of the acquired immune deficiency syndrome (AIDS): report of 39 autopsies from Vancouver, British Columbia.

Neuropathological findings from 39 acquired immune deficiency syndrome (AIDS) autopsies of primarily neurologically symptomatic patients and 7 brain biopsies from AIDS patients performed at St. Paul's Hospital, Vancouver, British Columbia are reported. Autopsy findings included human immunodeficiency virus-1 (HIV)-type multinucleated giant cell (MNGC)-associated encephalitis seen in 17 patients, toxoplasmosis in 7 patients, and cytomegalovirus encephalitis and/or microglial nodule-associated nuclear inclusions in brain parenchyma in 9 patients. Central nervous system lymphoma was identified in 11 autopsy patients and in 4 of 7 brain biopsies. Infectious processes including HIV encephalitis were seen in 10 of 11 autopsied patients with lymphoproliferative lesions in the brain parenchyma, while 40% of patients without lymphoma had HIV-type MNGC or opportunistic infections. CNS lymphoma was not significantly increased in incidence in patients with a clinical history of zidovudine treatment, but increased duration of survival after the diagnosis of AIDS was associated with increased incidence of lymphoma in both untreated and zidovudine-treated patients. Patients displaying HIV MNGC within microglial nodules had a shorter mean duration of survival after diagnosis of AIDS than those patients with HIV encephalitis with dispersed MNGC, white matter vacuolation, and gliosis.