Temporo-spatial analyses define epileptogenic and functional zones in a case of Dyke–Davidoff–Masson syndrome

Dyke–Davidoff–Masson syndrome (DDMS) is a rare epilepsy syndrome that is characterized by cerebral hemiatrophy, homolateral skull hyperplasia, hyperpneumatization of the paranasal sinuses, seizures with or without mental retardation, and contralateral hemiparesis. We describe a case of DDMS in a 40-year-old female who had complex partial seizures with occasional secondary generalization since the age of 4 years. Her seizure frequency was 10–20 seizures/month even though she took four antiepileptic drugs. We applied magnetic resonance imaging (MRI), positron emission tomography (PET), functional MRI, and invasive electroencephalography (EEG) to define her epileptogenic and functional zones. Brain MRI showed prominent atrophy in the left frontal dorsal and lateral regions and mild atrophy of the left superior temporal gyrus and left parietal gyri. Interictal PET revealed decreased glucose metabolism in the atrophic regions. Functional MRI demonstrated that the inferior frontal and inferior parieto-occipital regions of the right hemisphere were activated by language testing. Invasive EEG revealed that the left lateral temporal lobe was the sole source of her seizures. Our results imply that the “metabolic border zone” rather than the atrophic region plays an important role in seizure activity, and that reorganization of functional zones occur after cerebral damage early in life.     

Magnetic resonance imaging of childhood Guillain–Barre syndrome

Objective  

To describe the spinal magnetic resonance imaging (MRI) features in children with Guillain–Barre syndrome (GBS) and to investigate the correlation with the clinical/laboratory findings.     

Magnetic resonance imaging findings of mixed neuronal–glial tumors with pathologic correlation: a review

Mixed neuronal–glial tumors are rare, and MRI diagnosis of them presents a challenge. In this review, we discuss the MRI findings of ganglioglioma, anaplastic ganglioglioma, desmoplastic infantile ganglioglioma, papillary glioneuronal tumor, rosette-forming glioneuronal tumor, and primary diffuse leptomeningeal glioneuronal tumor with clinicopathologic correlation. There is overlap of imaging features both with each other and some other tumors, which complicates diagnosis. The combination of imaging findings and the age, location, and appropriate clinical picture should allow the radiologist and the clinicians to raise a provisional diagnosis of a mixed neuronal glial tumor, and guide patient management.     

Early electrodiagnostic findings in Guillain-Barré syndrome

CONTEXT: Guillain-Barré syndrome (GBS) is the foremost cause of acute, generalized, peripheral neuropathic weakness. Although nerve conduction studies are a diagnostic aid, the characteristic electrical changes may not evolve for several weeks. Early diagnosis of GBS is important, however, because early treatment has been shown to improve outcome. OBJECTIVES: To describe the electrodiagnostic abnormalities detectable in the first week of GBS, to determine if there are early patterns suggestive of GBS, and to identify the percentage of patients whose condition can be diagnosed with reasonable certainty in the first week. DESIGN AND SETTING: We retrospectively reviewed the medical records of all patients admitted to the Cleveland Clinic Foundation, Cleveland, Ohio, having the discharge diagnosis GBS during the past 16 years. Patients who underwent nerve conduction studies within 7 days of muscle weakness were selected for this study. RESULTS: The H reflex was absent in 30 (97%) of 31 patients. Nineteen patients (61%) had low-amplitude or absent sensory nerve action potential (SNAP) in the upper extremity. Fifteen patients (48%) overall, including 21 (67%) of the 31 patients, including 14 (67%) of the 21 patients younger than 60 years, had an abnormal upper extremity SNAP combined with a normal sural SNAP. Other findings included an abnormal F wave (25 patients [84%]), reduced compound muscle action potential amplitude (22 patients [71%]), prolonged distal latency (20 patients [65%]), temporal dispersion (18 patients [58%]), slowed motor conduction velocity (16 patients [52%]), and motor conduction block (4 patients [13%]). Definite diagnosis was possible in 17 patients (55%), but not commonly until the fifth day. CONCLUSIONS: The H reflex is the most sensitive test for early GBS. Upper extremity SNAPs are also frequently abnormal in early GBS. Absent H response, abnormal F wave, and abnormal upper extremity SNAP combined with a normal sural SNAP are characteristic of early GBS. If multiple nerves are tested, definite diagnosis is possible in half the patients, but not until the fifth day after the onset of symptoms.     

New findings in the ataxia of Charlevoix–Saguenay

The aim of the study was to enhance our understanding of the pathogenesis of the ataxia of Charlevoix-Saguenay, based on the findings presented herein. Five patients with a molecular diagnosis of this disease underwent clinical, radiological, ophthalmologic and electrophysiological examinations. Five novel mutations, which included nonsense and missense variants, were identified, with these resulting in milder phenotypes. In addition to the usual manifestations, a straight dorsal spine was found in every case, and imaging techniques showed loss of the dorsal kyphosis. Cranial MRI demonstrated hypointense linear striations at the pons. Tensor diffusion MRI sequences revealed that these striations corresponded with hyperplastic pontocerebellar fibres, and tractographic sequences showed interrupted pyramidal tracts at the pons. Ocular coherence tomography demonstrated abnormal thickness of the nerve fibre layer. Electrophysiological studies showed nerve conduction abnormalities compatible with a dysmyelinating neuropathy, with signs of chronic denervation in distal muscles. The authors suggest that the hyperplastic pontocerebellar fibres compress the pyramidal tracts at the pons, and that the amount of retinal fibres traversing the optic discs is enlarged. These facts point to the contribution of an abnormal developmental mechanism in the ataxia of Charlevoix-Saguenay. Accordingly, spasticity would be mediated by compression of the pyramidal tracts, neuromuscular symptoms by secondary axonal degeneration superimposed on the peripheral myelinopathy, while the cause of the progressive ataxia remains speculative. The distinctive aspect of the dorsal spine could be of help in the clinical diagnosis.     

Magnetic resonance imaging diagnosis of acute Guillain-Barré syndrome in children

The present study examined 24 children with acute Guillain-Barré syndrome using magnetic resonance imaging (MRI) plain scans and fat-suppressed enhanced T1-weighted imaging (T1WI) scans.Axial MRI plain scans centering on the medullary conus were positive in nine patients (38%).These displayed variable thickening involving the cauda equina with isointensity on T1WI and isointensity or slight hyperintensity on T2WI.False negatives were obtained in patients with cervical and cranial nerve symptoms.Contrast enhancement of T1WI with fat suppression was positive in all patients in the cauda equina with varied thickening and enhancement centering on the medullary conus.Five patients (36%) were positive in the cervical nerves and 3 patients (50%) were positive in the cranial nerves.These patients had corresponding cervical and cranial nerve symptoms,respectively.Patients with serious clinical symptoms in the lower limbs exhibited obvious involvement of the cauda equina by MRI.Statistical analysis revealed a positive correlation between the extent of enlargement of the cauda equina,centering on the medullary conus,and cerebrospinal fluid protein concentration.     

Functional imaging in Tourette’s syndrome

The cause or causes of Tourette's syndrome (TS) remain unknown. Functional imaging studies have evaluated several implicated neurotransmitter systems and focused predominantly on the frequency or severity of tics. The results have been inconclusive and frequently contradictory with little light shed on pathogenetic mechanisms. However, metabolic derangements have been demonstrated within regions of the basal ganglia, limbic system and sensori-motor cortex and are in keeping with the concept of TS as both a motor and behavioral disorder. TS has long been regarded an involuntary movement disorder. However, many patients have stated that without the premonitory sensation, there would be no tics. For this reason, it has been suggested that the premonitory urge may be considered the involuntary component of TS and the performance of the tic merely a voluntary response. Future studies are needed to differentiate functional changes relating to urge from those associated with the performance of tics and tic suppression.     

Very early electrodiagnostic findings in Guillain-Barré syndrome

Electrodiagnostic studies play a key role in the evaluation of patients with Guillain-Barré syndrome (GBS). However, at early stages patients may not meet current neurophysiologic criteria. We report electrodiagnostic findings for 18 patients with suspected GBS within 4 days of clinical onset. Fifteen patients (83%) showed abnormality in the motor nerve conduction study. Prolonged distal motor latency (DML) was the most frequent demyelinating parameter (seen in 55% of patients). Abnormal late responses were noted in 14 patients (77%). Electrodiagnostic study of cranial nerves was abnormal in eight (44%), and motor nerve conduction velocity was abnormal in only six patients (23%). The study shows a predominant motor neuropathy pattern followed by a sural-sparing pattern; no patients showed a strictly normal electrodiagnostic study. Reduced distal compound muscle action potential and prolonged DML in the demyelinating range were associated with severity of GBS on admission. After the electrodiagnostic study, 5 patients (27%) already fulfilled electrodiagnostic criteria for acute inflammatory demyelinating polyneuropathy (AIDP), 1 (5%) for the axonal variant of GBS, and 13 (72%) were classified as equivocal. We conclude that exhaustive electrodiagnostic studies of patients with suspected GBS in very early stages are useful in the diagnosis and management of the condition.     

Detection of pediatric obstructive sleep apnea syndrome: history or anatomical findings?

ObjectiveTo assess how history and/or anatomical findings differ in diagnosing pediatric obstructive sleep apnea (OSA).MethodsChildren aged 2–18 years were recruited and assessed for anatomical (ie, tonsil size, adenoid size, and obesity) and historical findings (ie, symptoms) using a standard sheet. History and anatomical findings, as well as those measures significantly correlated with OSA, were identified to establish the historical, anatomical, and the combined model. OSA was diagnosed by polysomnography. The effectiveness of those models in detecting OSA was analyzed by model fit, discrimination (C-index), calibration (Hosmer–Lemeshow test), and reclassification properties.ResultsA total of 222 children were enrolled. The anatomical model included tonsil hypertrophy, adenoid hypertrophy, and obesity, whereas the historical model included snoring frequency, snoring duration, awakening, and breathing pause. The C-index was 0.84 for the combined model, which significantly differed from that in the anatomical (0.78, p = 0.003) and historical models (0.72, p < 0.001). The Hosmer–Lemeshow test revealed an adequate fit for all of the models. Additionally, the combined model more accurately reclassified 10.3% (p = 0.044) and 21.9% (p = 0.003) of all of the subjects than either the anatomical or historical model. Internal validation of the combined model by the bootstrapping method showed a fair model performance.ConclusionOverall performance of combined anatomical and historical findings offers incremental utility in detecting OSA. Results of this study suggest integrating both history and anatomical findings for a screening scheme of pediatric OSA.     

Neural correlates of recovery from Foix–Chavany–Marie syndrome

Cerebral reorganization during recovery after stroke has been investigated using functional imaging in patients with subcortical motor stroke. The functional correlates of recovery from anarthria, however, are yet unknown. A 48-year-old male patient recovering from complete anarthria after unilateral right-sided subcortical hemorrhagic stroke is described. The main outcome measures included clinical and neuroimaging data at three different time points (at the onset of symptoms, after 6 weeks and after 6 months). At 6 weeks, increased activations in the right and left frontal operculum were found and were followed by a trend towards normalization of the activation pattern at 6 months. These results suggest a role of anterior opercular regions in recovery from anarthria after subcortical stroke. Moreover, complete recovery is possible after such lesions.