Brainstem Dysfunction In Patients Research Articles

O97 Video head impulse test in evaluation of brainstem dysfunction in multiple sclerosis

Objectives The aim of this study was to investigate the role of the video head impulse test (vHIT) in the detection of brainstem lesions in patients with multiple sclerosis (MS). Methods One hundred thirty participants were enrolled: 66 healthy subjects (HC) (132 ears, 38 females, mean age 45.8 ± 13.7) and 64 MS patients (128 ears, 45 females, mean age 36.8 ± 9.1). The impulses of the head were delivered in 3 planes: lateral, right anterior-left posterior (RALP) and left anterior-right posterior (LARP) with a minimum of 5 head impulses in each plane and direction. vHIT pathology was defined if lateral gain or posterior/anterior slope was lower than 0.7. Results In HC there was no pathology on lateral and posterior canals, while 16 (12.5%) and 6 (4.7%) out of 128 ears had pathological results on lateral and posterior canals, respectively, in the MS group ( p p = 0.008, respectively). Posterior canal pathology was associated with higher EDSS ( p = 0.007). Mean gain of the lateral (0.900 ± 0.206 vs. 0.964 ± 0.167, p = 0.007, respectively) and slope of anterior canals (1.223 ± 0.248 vs. 1.338 ± 0.348, p = 0.005, respectively) was significantly reduced in MS group compared to HC. MS patients with clinically evident brainstem dysfunction had significantly higher percentage of pathologies of posterior canals p = 0.017. MS patients with brainstem lesions (specifically midbrain and pontine lesions) had significantly higher percentage of pathologies of posterior canals p = 0.039 ( p = 0,028 and p = 0.007, respectively). Discussion Current research has already shown the capability of vHIT to differentiate peripheral causes of vertigo from their central counterparts. However, several publications have shown that central causes of vertigo, especially brainstem stroke can influence vHIT results. Conclusion Our results indicate that vHIT can detect brainstem dysfunction in patients with MS. Significance vHIT can be impaired when central part of the vestibular system is damaged.

Video head impulse test can detect brainstem dysfunction in multiple sclerosis

BackgroundThe aim of this study was to investigate the potential role of video head impulse test (vHIT) in the detection of brainstem lesions in patients with multiple sclerosis (MS). MethodsSixty-eight participants were enrolled and divided into two groups: 39 healthy subjects (HC) (78 ears, 20 females, mean age 25,3±6,3) and 29 MS patients (58 ears, 14 females, mean age 33,7±7,7). Both groups underwent vHIT, and in MS group MRI was analyzed for the presence of brainstem lesions. vHIT pathology was defined as presence of overt saccades (<200ms) or lateral gain lower than 0.8 for lateral canal, and presence of overt saccades (<200ms) or posterior/anterior slope lower than 0.7. ResultsIn HC, decreased gain on horizontal canals was found in 8 out of 78 ears (11%), while 16 out of 58 ears (38%) had pathological results in the MS group. Mean gain of the lateral canals (60ms) was significantly reduced in MS group compared to HC (0.874±0143 vs. 0.954±0,170, p=0.004, respectively). Compared to HC overt saccades <200ms in the lateral canals (p=0.018) and in the posterior canals (p=0.011), overt saccades >200ms in lateral (p<0.001), anterior (p=0.019) and posterior canals (p=0.009), and covert saccades in the anterior (p=0.042) and posterior canals (p=0.046) were more frequent in the MS group. There was statistically significant association between the presence of BS MR lesions and bilateral pathology on vHIT for lateral semicircular canal (χ(1)=3.982, p=0.046). ConclusionThese results indicate that vHIT can detect brainstem dysfunction in patients with MS.

Brainstem auditory evoked potentials in neurophysiological assessment of brain stem dysfunction in patients with atherostenosis of vertebral arteries

To assess brain stem dysfunction in patients with hemodynamically significant stenosis of vertebral arteries (VA) using short latency brainstem auditory evoked potentials (BAEP). The study group included 50 patients (mean age 64±6 years) with hemodynamically significant extracranial VA stenosis. Patients with hemodynamically significant extracranial VA stenosis had BAEP abnormalities including the elongation of interpeak intervals I-V and peak V latency as well as the reduction of peak I amplitude. After transluminal balloon angioplasty with stenting of VA stenoses, there was a shortening of peak V latency compared to the preoperative period that reflected the improvement of brain stem conductive functions. Atherostenosis of vertebral arteries is characterized by the signs of brain stem dysfunction, predominantly in the pontomesencephal brain stem. After transluminal balloon angioplasty with stenting of VA, the improvement of brain stem conductive functions was observed.

Vestibular evoked myogenic potentials and MRI in early multiple sclerosis: Validation of the VEMP score

BackgroundTo validate the VEMP score as a measure of brainstem dysfunction in patients with the first symptom of multiple sclerosis (MS) (clinically isolated syndrome (CIS)) and to investigate the correlation between VEMP and brainstem MRI results. Methods121 consecutive CIS patients were enrolled and brainstem functional system score (BSFS) was determined. Ocular VEMP (oVEMP) and cervical VEMP (cVEMP) were analyzed for latencies, conduction block and amplitude asymmetry ratio and the VEMP score was calculated. MRI was analyzed for the presence of brainstem lesions as a whole and separately for the presence of pontine, midbrain and medulla oblongata lesions. ResultsPatients with signs of brainstem involvement during the neurological examination (with BSFS ≥1) had a higher oVEMP score compared to patients with no signs of brainstem involvement. A binary logistic regression model showed that patients with brainstem lesion on the MRI are 6.780 times more likely to have BSFS ≥1 (p=0.001); and also, a higher VEMP score is associated with BSFS ≥1 (p=0.042). Furthermore, significant correlations were found between clinical brainstem involvement and brainstem and pontine MRI lesions, and prolonged latencies and/or absent VEMP responses. ConclusionsThe VEMP score is a valuable tool in evaluation of brainstem involvement in patients with early MS.

Brainstem dysfunction in patients with late-onset Lennox-Gastaut syndrome: Voxel-based morphometry and tract-based spatial statistics study.

Background:There have been a few reports of patients who developed Lennox–Gastaut syndrome (LGS) in the second decades of their life.Objectives:The aim of this study was to investigate electroclinical presentation in patients with late-onset LGS. In addition, we evaluated structural abnormalities of the brain, which may give some clue about the common pathogenic pathway in LGS.Materials and Methods:We enrolled the patients with late-onset LGS. We collected electroclinical characteristics of the patients and evaluated structural abnormalities using voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis.Results:The three subjects were diagnosed with late-onset LGS. The patients have no mental retardation and normal background activities on electroencephalography (EEG), and they had generalized paroxysmal fast activities on EEG, especially during sleep. The TBSS analysis revealed that fractional anisotropy values in the patients were significantly reduced in the white matter of brainstem compared with normal controls. However, VBM analysis did not show any significant difference between the patients and normal controls.Conclusions:Patients with late-onset LGS have different clinical and EEG characteristics from those with early-onset LGS. In addition, we demonstrated that brainstem dysfunction might contribute to the pathogenesis of late-onset LGS.

Prognostic value of newborn hearing screening in patients with myelomeningocele.

Brainstem dysfunction occurs in a minority of patients with myelomeningocele (MMC), most of whom have Chiari Type II malformation. Some surgeons advocate early identification of these patients for craniocervical decompression to avoid significant mortality. The auditory brainstem response has been found to be abnormal in most children with MMC. The present study examines whether failure of routine newborn hearing screening (NHS) predicts brainstem dysfunction in MMC patients. The charts of 40 newborns with MMC and 50 newborns without MMC who stayed in the neonatal intensive care unit were reviewed. Results of NHS, brainstem symptoms, birth demographics, and surgical history were retrospectively examined. Differences in the presence and onset of brainstem symptoms by NHS result were assessed. Failure of NHS was more common among newborns with MMC who developed brainstem symptoms (31%, 4 of 13 patients) than among newborns without MMC (0%, 0 of 50 patients; p = 0.001). Among the 40 newborns with MMC, brainstem symptoms were more common in those who failed NHS (80%, 4 of 5 patients) than in those who passed (26%, 9 of 35 patients; p = 0.031). Respiratory symptom onset occurred later in patients who failed NHS (median 16 months) than among those who passed (median 0 months; p = 0.022). The positive and negative predictive values of NHS for brainstem dysfunction in MMC were 0.80 and 0.74, respectively. Results of NHS may help predict future brainstem dysfunction in patients with MMC and may be useful to incorporate into prognostic assessment and surgical decision making.

Reversible Coma Associated With Prolonged High-Dose Phenobarbital Therapy in Bilateral Sturge-Weber Syndrome

High-dose phenobarbital therapy is an effective treatment for refractory status epilepticus in children. The advantages of this therapy include milder adverse effects without limits for maximal phenobarbital levels or doses during the initial phase of treatment. However, little is known about the safety of continuing the treatment. We describe an infant with intractable epilepsy associated with bilateral Sturge-Weber syndrome who became comatose after 1(2/3) months of high-dose phenobarbital treatment. The patient regained consciousness as serum phenobarbital concentration decreased to below 40 microg/mL. The progression and recovery were also documented by electroencephalogram and brainstem auditory evoked potentials. The present case suggests that prolonged high-dose phenobarbital therapy may cause cerebral and brainstem dysfunction in patients with severe cerebrovascular diseases. The underlying baseline metabolic and perfusion deficit related to the disease can precipitate the neurological complication during long-term high-dose phenobarbital therapy.

P07. Localized brainstem dysfunction in patients with Parkinson’s disease and central pain

P07. Localized brainstem dysfunction in patients with Parkinson’s disease and central pain

Unusual Diagnosis in a Child Suffering From Juvenile Alexander Disease: Clinical and Imaging Report

Alexander disease is a rare, sporadic leukoencephalopathy characterized by white-matter abnormalities with frontal predominance and, as a rule, clinically associated with megalencephaly, seizures, spasticity, and psychomotor deterioration. We describe a boy who was diagnosed as affected by anorexia nervosa because of his refusal to eat, progressive weight loss, and psychologic disturbances. The observation of a hyperintense lesion on T(2)-weighed magnetic resonance images (MRIs) was initially explained as a pontine and extrapontine myelinolysis related to malnutrition. Following MRI and DNA analysis, we diagnosed a juvenile type of Alexander disease. Therefore, we can affirm the importance of the history and clinical examination to look for brainstem dysfunction in patients presenting with atypical anorexia nervosa.

Electrophysiological brainstem dysfunction in a child with Leigh disease

We evaluated brainstem dysfunction in a girl with Leigh disease. Neuroradiological and neurophysiological tests included brain magnetic resonance imaging, [ 123I]IMP single-photon emission computed tomography (SPECT), auditory brainstem responses (ABRs), short-latency somatosensory evoked potentials (SSEPs), electrically elicited blink reflexes (BRs) and all night polysomnography (PSG). The basal ganglia and midbrain contained areas of low accumulation on [ 123I]IMP SPECT images. Serial analysis of ABRs and SSEPs showed progressive disturbances of the brainstem wave components. The R2 components of the BRs were impaired. All night PSG revealed disturbances in both the tonic and phasic components of REM sleep. These findings suggested the multimodality tests in combination with neuroradiologic examinations are useful for assessing brainstem dysfunction in patients with Leigh disease.

Blink reflex in cerebral palsy: evaluation of late components in patients with normal auditory brainstem responses.

The electrically elicited blink reflex was examined and evaluated quantitatively in 60 controls and seven patients with cerebral palsy due to perinatal asphyxia who exhibited normal auditory brainstem responses. In the controls, the early component (R1) latency changed slightly from infancy to adulthood, and the late component (R2 and R2') latencies decreased to adult values by 4 to 6 years of age. The electromyographic activity of R2 and R2' increased later and became mature in the young adolescent period. Prolonged R2 latency and decreased R2 amplitude were observed more frequently than R1 abnormalities in the patients. The electromyographic activity of R2 in the patients was lower than that in control subjects more than 13 years old. Almost all patients showed bilateral cerebral atrophy and dilated lateral ventricles, but only one patient exhibited distinct pontine atrophy on cranial computed tomographic scan. These electrophysiologic abnormalities suggest that decreased excitability of interneurons of the reflex arc was present in the patients, particularly in older ones. The blink reflex test seems to be more sensitive than the auditory brainstem response for detecting brainstem dysfunction in patients with cerebral palsy due to neonatal asphyxia.

Brainstem auditory evoked potentials in dizziness.

To investigate the role of brainstem dysfunction in patients with dizziness, Brainstem Evoked Responses were recorded, and results of 100 such cases are presented. The present study further emphasizes the fact that dizziness is a symptom complex and careful evaluation of these patients is necessary. If a systematic approach is used, then a correct diagnosis can be achieved in over 95% of the cases. Vascular insufficiency of the brainstem can present as dizziness and may precede a catastrophic vascular infarction by weeks and months. Early recognition of the problem is of paramount importance, since anticoagulation therapy can be started early or other surgical correctable measures can be undertaken to prevent catastrophic infarction.