Vibratory perception threshold in patients with mild multiple sclerosis

Brain and cervical spinal cord MRI correlates of sensorimotor impairment in patients with multiple sclerosis

BACKGROUND

Cervical spinal cord (cSC) lesions and atrophy contribute to disability in multiple sclerosis (MS), but associations with specific sensorimotor dysfunction require further exploration.

OBJECTIVE

To investigate the associations of brain and cSC magnetic resonance imaging (MRI) measures with sensorimotor impairment in MS.

METHODS

One hundred fifty-one MS patients and 69 healthy controls underwent 3T MRI and clinical assessments including Expanded Disability Status Scale (EDSS), 9-hole peg test (9-HPT), finger tapping test (FTT), timed 25-foot walk test (T25FWT), and vibration detection threshold (VDT). Random forest ranked brain (T2-hyperintense lesion volume (T2-LV) and normalized deep gray matter (GM), cortical and white matter (WM) volumes) and cSC (T2-LV and total, GM, and WM cross-sectional areas (CSAs) at C2/C3 level) MRI measures relevance in explaining EDSS milestones (EDSS ⩾3.0, ⩾4.0, and ⩾6.0), VDT, pyramidal and sensory functional systems (P-FS and S-FS ⩾2), and motor tests impairment.

RESULTS

Various combinations of brain and cSC MRI measures explained EDSS milestones (area under the curve (AUC) =0.879-0.900), VDT (R2 = 0.194), and impaired P-FS (AUC = 0.820), S-FS (AUC = 0.795), 9-HPT (AUC = 0.793), FTT (AUC = 0.740), and T25FWT (AUC = 0.825). cSC GM CSA was the most informative feature for all outcomes, except 9-HPT.

CONCLUSION

cSC MRI measures, especially GM CSA, explain EDSS and sensorimotor dysfunction better than brain measures in MS.

Peripheral neuropathy in patients with multiple sclerosis

OBJECTIVES

To determine the prevalence and severity of neuropathic pain, sudomotor dysfunction and abnormal vibration perception in patients with MS.

METHODS

73 patients with MS and 32 age-matched healthy controls underwent assessment of expanded disability severity score (EDSS), DN4 to assess neuropathic pain, electrochemical skin conductance (ESC) to assess sudomotor function and vibration perception threshold (VPT).

RESULTS

Patients with MS had a higher DN4 score (p < 0.001) with 14% fulfilling the criteria for neuropathic pain elevated VPT (p < 0.001) and lower ESC on the feet (p < 0.001) and hands (p < 0.001) compared to control participants. ESC on the feet (32% of MS patients) and hands (30% of MS patients) were lower, and DN4 (77% of MS patients) and VPT (64% of MS patients) were greater than 2SD of the healthy control values, respectively. EDSS correlated with the number of relapses (r = 0.564, p < 0.001), VPT (r = -0.457, < 0.001) and ESC on the feet (r = -0.268, p = 0.023).

CONCLUSIONS

Patients with multiple sclerosis have evidence of sudomotor dysfunction and elevated vibration perception, which were associated with neurological disability from MS.

Measures of sensation in neurological conditions: a systematic review

Objective: To systematically review the psychometric properties and clinical utility of measures of sensation in neurological conditions to inform future research studies and clinical practice.

Data sources: Electronic databases (MEDLINE, CINAHL, EMBASE and AMED) were searched from their inception to December 2010.

Review methods: Search terms were used to identify articles that investigated any sensory measures in neurological conditions. Data about their psychometric properties and clinical utility were extracted and analyzed independently. The strength of the psychometric properties and clinical utility were assessed following recommendations. 1

Results: Sixteen sensory measures were identified. Inter-rater reliability and redundancy of testing protocols are particular issues for this area of assessment. Eleven were rejected because they were not available for a researcher or clinician to use. Of the remaining five measures, the Erasmus MC modifications of the Nottingham Sensory Assessment and the Sensory section of the Fugl–Meyer Assessment showed the best balance of clinical utility and psychometric properties.

Conclusion: Many measures of sensory impairment have been used in research but few have been fully developed to produce robust data and be easy to use. At present, the sensory section of the Fugl–Meyer Assessment and the Erasmus MC modifications of the Nottingham Sensory Assessment show the most effective balance of usability and robustness, when delivered according to the operating instructions.

Somatosensory evoked potentials and sensory involvement in multiple sclerosis: comparison with clinical findings and quantitative sensory tests

Sensory disturbances are one of the most common findings in patients with multiple sclerosis (MS). However, they are usually assessed at the standard neurological examination only. Quantitative Sensory Tests (QSTs) for temperature and vibratory sense allow a more objective evaluation. In a group of 19 clinically definite MS patients, we compared vibratory and temperature thresholds with sensory symptoms or signs at clinical neurological examination and somatosensory evoked potentials (SEPs) at the four limbs. The frequency of abnormalities of clinical symptoms/signs, vibration threshold and median SEPs were 69%, 33% and 55%, respectively. Correlation between degree of abnormality of SEPs and clinically assessed vibration sense (V) was statistically significant (P<0.007; Spearmann rank coefficient), as well as between SEPs and vibration perception threshold (P<0.02). Clinical evaluation of thermal sense did not show false positive results compared to quantitative thermal threshold, but false negative findings (35%). This study suggests that the combined use of vibration threshold and SEPs allows a better objectivation of sensory function, allowing the detection of subclinical abnormalities and possibly reducing the number of false positive results introduced by clinical assessment. Moreover QSTs are to be preferred to clinical evaluation in the assessment of thermal sense, due to their superior sensitivity.

Vibratory perception thresholds in the female genital region

Vibratory perception thresholds (VPT) were determined in the hands, feet and genital region by means of an electromagnetic vibrator and expressed in terms of amplitude of stimulator movements measured by an accelerometer. Eight healthy women volunteers aged 27-44 were examined on 8-11 occasions each during the menstrual cycle. Ninety-five further women, aged 35-45 were consecutively selected from the waiting list for hysterectomy for non-malignant disorders and examined on one occasion each. VPT measurements were correlated to menstrual phases and blood oestradiol values. In the healthy volunteer group the mean VPT for clitoris was 0.27 mu (SD 0.10, range 0.09-0.48), for hands 0.19 mu (SD 0.09, range 0.05-0.37) and feet 0.51 mu (SD 0.39, range 0.17-1.5). In none of the two groups were there any significant differences between the VPTs of the different phases of the menstrual cycles nor was there any significant correlation between VPT and serum oestradiol levels.