Late Component of the Trigemino-Cervical Reflex: Clinical and Neuroradiological Correlations.

INTRODUCTION: The authors aimed to analyze the possible relationship of the late response of trigemino-cervical reflex (TCR) with various clinical conditions having brainstem lesions and lesion localizations in the brainstem. METHODS: The authors enrolled 30 healthy subjects, 16 patients with stroke, 14 patients with multiple sclerosis (MS), and 9 patients with neuro-Behçet disease. All patients had at least one MRI, and lesion localization was classified into midbrain, pons, medulla oblongata, or their combinations. The TCR was recorded simultaneously from bilateral sternocleidomastoid and splenius capitis muscles. RESULTS: There was no significant difference based on lesion localization within the brainstem. Trigemino-cervical reflex latency was significantly longer in patients with MS compared with all other groups (P < 0.005 for each comparison). The Receiver Operating Characteristic curve analysis of sternocleidomastoid showed a cut-off value of 76.9 ms with 44% sensitivity and 92.7% specificity to predict MS. Similarly, the authors determined a cut-off value of 61.5 ms of splenius capitis latency with 38.5% sensitivity and 91.5% specificity to predict MS. CONCLUSIONS: This study showed that TCR might be abnormal in a given patient with one brainstem lesion, independently from the lesion localization. This may be attributed to a broad network of TCR at the brainstem. Thus, abnormally delayed TCR responses can be used as a tool for the discrimination of MS among other brainstem lesions.

Treatment of multiple sclerosis-related trigeminal neuralgia with onabotulinumtoxinA.

BACKGROUND: The effectiveness of onabotulinumtoxinA (BTX-A) has been established in primary trigeminal neuralgia (TN). However, to the best of our knowledge, the efficacy of BTX-A in secondary TN has not yet been studied. OBJECTIVE: This study aimed to investigate the efficacy of BTX-A treatment in patients with multiple sclerosis-related trigeminal neuralgia (TN-MS) and compare the efficacy of BTX-A treatment between patients with primary trigeminal neuralgia (TN-P) and patients with TN-MS. METHODS: This was a retrospective medical record-review study. Demographic and clinical features and severity and frequency of pain before and 2 weeks after the BTX-A administration were extracted from the patient files. BTX-A was injected into the painful area subcutaneously and/or submucosally. BTX-A injections were performed by the same physician using the same methods. A reduction in severity and/or frequency of pain ≥50% was considered therapeutic efficacy. RESULTS: Fifty-three patients were included in this study. We classified 22 (42%) as TN-P and 31 (58%) as TN-MS. Treatment with BTX-A was effective in 16 of 31 (52%) patients with TN-MS and 10 of 22 (45%) with TN-P. BTX-A treatment was less effective in patients with a history of interventional treatments and more effective in patients with concomitant continuous pain (p = 0.007; odds ratio [OR]: 0.020-0.53 and p = 0.047; OR: 0.046-0.98, respectively). CONCLUSION: The BTX-A treatment was found to be effective in at least half of our cohort with TN-MS. Concomitant continuous pain and history of interventional treatments to the trigeminal nerve or ganglion might be predictive factors for the efficacy of BTX-A treatment.

Prepulse inhibition and recovery of trigemino-cervical reflex in patients with cervical dystonia.

OBJECTIVE: We aimed to analyze the prepulse inhibition (PPI) and recovery rate (R) of the trigeminocervical reflex (TCR) in patients with cervical dystonia (CD). METHODS: We enrolled 15 patients with CD and 16 healthy subjects. TCR was recorded over splenius capitis after infraorbital nerve stimulation. For TCR-PPI, we applied a prepulse stimulus to the left second finger 100 ms prior to the test stimulus and the percentage of change of response to test stimulus was calculated. For TCR-R, we applied paired infraorbital stimuli at interstimulus interval (ISIs) of 300 ms and the percentage of change of the second compared to the first response was calculated. RESULTS: TCR-PPI and TCR-R values were higher (less inhibition and greater recovery) on both sides in the patient group compared to healthy subjects. There was high correlation between TCR-PPI and TCR-R on both sides in patients with dystonia (p < 0.005). We did not find any significant relationship between TCR-R or TCR-PPI and side of dystonic posture. CONCLUSIONS: We showed disturbed modulation of TCR in CD patients. In CD, a general inhibition of the inhibitory pathways and facilitation of the excitatory pathways occur. Although TCR was recorded directly on the affected muscles in CD, symmetric abnormal TCR findings in CD suggest that these findings are probably secondary to altered function of higher order centers rather than being directly related to the pathophysiological process.

Ulnar Neuropathy at Elbow in Patients With Type 2 Diabetes Mellitus.

PURPOSE: In diabetes mellitus (DM), upper extremity entrapment neuropathies are suggested to be a component of polyneuropathy (PNP). Our aim is to examine the presence of ulnar neuropathy at the elbow (UNE) and its relation to other findings including PNP in symptomatic and asymptomatic type-2 DM patients who were admitted for routine examinations. METHODS: The study included all cases referred for electromyography because of type-2 DM between November 2017 and May 2018. Demographic and clinical characteristics were recorded. Routine electromyography examinations in all cases included the following: bilateral motor conduction of the median, ulnar, peroneal, and tibial nerves and sensory conduction of the median, ulnar, and sural nerves. For ulnar nerve examination, stimuli were given at the wrist, below the elbow, and above the elbow. Electrophysiological findings were evaluated according to the American Association of Neuromuscular and Electrodiagnostic Medicine criteria. RESULTS: Eighty-two patients with type-2 DM and 144 upper extremities were included in the study. Of the 82 patients who participated in the study, 3 had findings suggesting ulnar neuropathy, and electrophysiology confirmed UNE in only one. Electrophysiological studies showed UNE in 36 patients. Other diagnoses identified by electrophysiology were carpal tunnel syndrome and PNP. Ulnar neuropathy at the elbow was more commonly associated with PNP compared with carpal tunnel syndrome. Gender and PNP were independent risk factors for the development of UNE. CONCLUSIONS: Although the majority of diabetic patients were asymptomatic for the UNE, approximately one third of all patients with DM were found to have UNE. Ulnar neuropathy at the elbow is closely related with PNP.

Brainstem reflexes in neuro-Behçet disease.

We hypothesized that brainstem responses may allow detection of functional brainstem changes in patients with neuro-Behçet Disease (NBD). Thus, we recorded electrically-induced blink reflex (eBR), auditory blink reflex (aBR) and electrically-induced masseter inhibitory reflex (eMIR) in 16patients with NBD. However, these neurophysiological tests proved to have a poor overall sensitivity compared to neuroimaging for the diagnosis of brainstem lesions. They also showed low sensitivity for the differential diagnosis of focal pontine lesion versus diffuse brainstem disease in NBD.

Persistent anterograde amnesia due to the artery of Percheron occlusion: a case report.

Bilateral thalamic infarction involving the artery of Percheron (AOP) can cause diagnostic difficulties due to the varying clinical presentations. AOP infarcts presented with isolated memory impairment are not common and the factors affecting the persistence of memory disorders are still unknown. A 41-year-old male patient was hospitalized with acute unconsciousness. MRI disclosed bilateral paramedian thalamic infarction The patient had isolated memory deficit and his anterograde amnesia continued without any change in the past decade. More cases might answer the questions concerning the intra- and extra-thalamic structures responsible for the amnesic syndrome and the factors affecting the persistence of the symptoms.