Clinico-radiological correlation of magnetic resonance imaging findings in patients with idiopathic intracranial hypertension.

PURPOSE: Although several studies have reported imaging findings associated with idiopathic intracranial hypertension (IIH), less is known about the correlation between imaging findings and IIH-related symptoms or signs. Our study aimed to determine if clinical features of IIH are correlated with magnetic resonance imaging (MRI) features. METHODS: A retrospective chart review was conducted on consecutive patients presenting at the neuro-ophthalmology department over the last 15 years. All patients diagnosed with IIH were identified and those with available MRI were included in the final analysis. All MRI images were reviewed by a neuroradiologist blinded to the presenting symptoms and signs. Statistical analysis was performed to determine the correlation between the MRI findings with each clinical symptom or sign. RESULTS: Thirty-one out of 88 patients with the initial diagnosis of IIH had MRI available and were included in the study. Significant correlations were observed between colour vision and amount of perineural fluid around the optic nerve on MRI (r = - 0.382; p = 0.004), disc assessment and intraocular optic nerve protrusion (r = 0.364; p = 0.004), disc assessment and perineural fluid around the optic nerve (r = 0.276; p = 0.033) and disc assessment and venous sinus stenosis (r = 0.351; p = 0.009). CONCLUSION: Our study highlights correlations between imaging and clinical findings of IIH. MRI findings in IIH may be useful in ruling out ominous causes of intracranial pressure and risk stratifying ophthalmologic intervention and management of patients with headaches possibly due to IIH.

Clinical variability in maternally inherited leber hereditary optic neuropathy with the G14459A mutation.

Spasticity and dystonia have been associated with mitochondrial (mt) DNA mutations at A11696G, G14459A, and T14596A. We describe the clinical features and molecular analysis of two Caucasian pedigrees with the 14,459 guanosine (G) --> adenine (A) transition. The maternally inherited Leber hereditary optic neuropathy (LHON) phenotypes showed extreme clinical variability and the only screening test that was abnormal in the patient with spasticity/dystonia was a high T2 signal in the putamen bilaterally. The male patient in the second pedigree showed features of optic neuropathy without spasticity/dystonia. These results further support that the 14,459 G --> A transition mutation is causally related to LHON and spasticity/dystonia.

Genetic susceptibility to MS: a second stage analysis in Canadian MS families.

Four published genome screens have identified a number of markers with increased sharing in multiple sclerosis (MS) families, although none has reached statistical significance. One hundred and five markers previously identified as showing increased sharing in Canadian, British, Finnish, and American genome screens were genotyped in 219 sibling pairs ascertained from the database of the Canadian Collaborative Project on Genetic Susceptibility to MS (CCPGSMS). No markers examined met criteria for significant linkage. Markers located at 5p14 and 17q22 were analyzed in a total of 333 sibling pairs and attained mlod scores of 2.27 and 1.14, respectively. The known HLA Class II DRB1 association with MS was confirmed (P<0.0001). Significant transmission disequilibrium was also observed for D17S789 at 17q22 (P=0.0015). This study highlights the difficulty of searching for genes with only mild-to-moderate effects on susceptibility, although large effects of specific loci may still be present in individual families. Future progress in the genetics of this complex trait may be helped by (1) focussing on more ethnically homogeneous samples, (2) using an increased number of MS families, and (3) using transmission disequilibrium analysis in candidate regions rather than the affected relative pair linkage analysis.

Correlation of the pilo-pupil ratio average, a new test for autonomic denervation, to the severity of diabetic retinopathy.

OBJECTIVE: To evaluate the association between the degree of diabetic retinopathy and autonomic neuropathy, and to test whether ocular parasympathetic denervation is correlated to the degree of diabetic retinopathy. DESIGN: Cross-sectional pilot study. SETTING: The tertiary ophthalmic centre for the Atlantic provinces in Halifax. PATIENTS: Twelve randomly selected patients (six women and six men with a mean age of 36.6 years) with insulin-dependent diabetes mellitus who had diabetic retinopathy. OUTCOME MEASURES: Degree of diabetic retinopathy, hemoglobin Alc level, orthostatic change in systolic and diastolic blood pressure and in serum catecholamine levels, degree of pupillary supersensitivity to 0.125% pilocarpine (pilo-pupil ratio average [PPRA]). RESULTS: The degree of diabetic retinopathy was significantly correlated with the duration of diabetes (p = 0.035), the hemoglobin Alc level (p = 0.004), the orthostatic change in diastolic blood pressure (p = 0.022) and the PPRA (p = 0.0007). CONCLUSIONS: The degree of diabetic retinopathy was significantly correlated with autonomic neuropathy and with the PPRA. Given these results, further study is indicated to determine whether autonomic neuropathy is a predictor of the severity of diabetic retinopathy.

Auditory temporal resolution in multiple sclerosis.

Disturbances of hearing in multiple sclerosis patients have been variably reported, likely because standard audiologic testing emphasizes assessment of peripheral, rather than central, auditory function. This study investigated a group of patients with multiple sclerosis (MS), prospectively selected on the basis of magnetic resonance imaging (MRI) scans. Five of these patients had demyelinating lesions that included the rostral auditory fibre tracts, while another seven patients had lesions restricted to brainstem auditory sites. A further four had no lesions in the distribution of their auditory pathways. A comprehensive battery of audiometric tests, including standard audiometry and retrocochlear testing, was performed. In addition, their findings on electrophysiologic testing, including auditory brainstem responses (ABR) and middle latency responses (MLR), were studied. Finally, their performances in gap detection and speech recognition in continuous and interrupted background noise were examined to assess their auditory temporal resolution. The MS patients were found to be selectively impaired under the interrupted masker of this speech-in-noise paradigm, confirming a temporal processing defect. Furthermore, these patients' performances suggested a predominant role of forebrain pathways in mediating auditory temporal resolution.

Pain prevalence, severity and impact in a clinic sample of multiple sclerosis patients.

Previous studies have reported variable prevalence of pain in multiple sclerosis (MS) and have not documented the impact of pain on daily living. In this consecutive series, we report on data collected from structured interviews with 85 patients seen within a 16-month period at a regional referral clinic. The prevalence of pain for the month preceding assessment was 53%. There were no significant differences between patients who did and those who did not report pain on the basis of patient demographics (age, gender) and disease characteristics (disease subtype, duration and neurologic symptom severity). Disease duration and neurologic symptom severity were significantly correlated with the number of hours of pain per week but were not correlated with pain severity, the number of pain sites or pain-related distress. There was wide variability in the number of pain hours/week reported with 17.6% of the sample reporting continuous pain for the month preceding assessment. Sixty-five percent of patients with pain reported taking medications for pain and 90% of these patients evaluated their medication(s) as 50% effective or better. Nevertheless, patients with pain reported poorer mental health and more social-role handicap. Discussion focuses on the need for routine assessment of pain and the comprehensive evaluation of the effectiveness of pain interventions in the therapeutic management of patients with MS.

Cerebrospinal fluid protein and opening pressure in idiopathic intracranial hypertension (pseudotumor cerebri).

We studied the relationship between the CSF protein concentration and the degree of elevation of the CSF opening pressure in 177 patients with idiopathic intracranial hypertension (pseudotumor cerebri). There was no linear correlation between the CSF protein and opening pressure. In addition, low CSF protein (less than 20 mg/dl) was present in only 26% of the patients. Our findings fail to confirm previous reports of an inverse relationship between the CSF opening pressure and CSF protein as well as low CSF protein in these patients.

Significance of CT and MR findings in sphenoid sinus disease.

Disorders of the paranasal sinuses, particularly the sphenoid sinus, can be associated with significant disorders of the optic and other cranial nerves. We examined 100 consecutive routine CT scans, 100 posterior fossa CT scans, and 100 MR scans to look for evidence of sinus disease, especially of the sphenoid sinus. The sphenoid sinus was abnormal in 7% of scans by all methods. Other sinuses were more frequently abnormal, including maxillary (23%), ethmoid (34%), and frontal (16%). Although MR was more sensitive in detecting sinus inflammation in the ethmoid and maxillary sinuses, the frequency of visible sphenoid sinus abnormalities detected by MR was not significantly greater when compared with CT. Of those patients with abnormal sphenoid sinuses, 24% had visual problems associated with the abnormality.

Asymmetric papilledema and visual loss in pseudotumour cerebri.

We report the case of a 26 year old obese woman who presented with intermittent headaches and blurred vision in her left eye (OS) and on clinical examination had an enlarged visual field blind spot OS with OS disc edema. After an extensive neurologic work up including two nondiagnostic lumbar punctures, a clinical diagnosis of OS anterior ischemic optic neuropathy was made. Gradual progression of visual field loss OS prompted reassessment of the diagnosis and intracranial pressure was confirmed to be markedly elevated by usage of a subarachnoid monitoring bolt, thus establishing the diagnosis of pseudotumour cerebri. An optic nerve sheath fenestration was performed OS with subsequent reversal of the progressive visual field loss.

Orientation-selective visual loss in patients with Parkinson's disease.

Visual contrast sensitivity was measured using 2 cycle/deg sinewave gratings of different orientations in 10 patients with Parkinson's disease and in 15 age-matched controls. Loss of visual contrast sensitivity was found in 6 patients, all of whom had normal visual acuity. Visual loss depended on grating orientation; in all cases the maximum sensitivity loss was for the horizontal. Sensitivity loss was most marked at a temporal frequency of 4 to 8 Hz. Visual fields gave no hint of the orientation selectivity. We conclude that orientation selectivity implicates visual cortical cells in Parkinson's disease. We tentatively suggest that a preferential loss of contrast sensitivity to horizontal gratings might be due to a functional abnormality in the striate cortex that relatively spares the extrastriate cortex. The dependence of visual loss on temporal frequency combined with the sparing of visual acuity might possibly be understood if Parkinson's disease preferentially affects the visual pathway leading from the retina to cortex via the magnocellular layer of the lateral geniculate nucleus. There is an intriguing similarity between the pattern of visual loss in Parkinson's disease and in multiple sclerosis.