Intracranial hypotension following traumatic brain injury: a diagnostic and therapeutic challenge.

BACKGROUND: Intracranial hypotension (IH) is a recognised cause of coma, however, the diagnosis is often challenging, especially in patients with superimposed traumatic brain injury (TBI). CASE REPORT: We report a case of a 67-year-old patient who became comatose following evacuation of bilateral acute subdural haematomas with concurrent respiratory failure. Imaging and intraparenchymal intracranial pressure (ICP) monitoring confirmed secondary IH. She was managed with an epidural blood patch, and a 72 hours period in the trendelenberg position guided by ICP monitoring and clinical assessment. She subsequently made an excellent neurological recovery from an initial Glasgow coma scale (GCS) of 3 to a GCS of 15. CONCLUSION: A diagnosis of secondary IH can easily be missed in patients who have suffered a primary brain injury. In patients with a poor neurological recovery, clinicians should rule out secondary IH as a potential cause as immediate treatment can lead to a profound clinical improvement

Benzodiazepine receptor binding in cerebellar degenerations studied with positron emission tomography

We used positron emission tomography with [ 11 C]flumazenil to study gamma‐aminobutyric acid type A/benzodiazepine receptor binding quantitatively in the cerebral hemispheres, basal ganglia, thalamus, cerebellum, and brainstem of 72 subjects, including 14 with multiple system atrophy of the ataxic (olivopontocerebellar atrophy) type, 5 with multiple system atrophy of the extrapyramidal/autonomic (Shy‐Drager syndrome) type, 18 with sporadic olivoponto‐cerebellar atrophy, 15 with dominantly inherited olivopontocerebellar atrophy, and 20 normal control subjects with similar age and sex distributions. In comparison with data obtained from the normal control subjects, we found significantly Decemberreased ligand influx in the cerebellum and brainstem of multiple system atrophy patients of the olivopontocerebellar atrophy type and in patients with sporadic olivopontocerebellar atrophy, but not in patients with multiple system atrophy of the Shy‐Drager syndrome type. Despite these differences in ligand influx, benzodiazepine binding was largely preserved in the cerebral hemispheres, basal ganglia, thalamus, cerebellum, and brainstem in patients with multiple system atrophy of both types as well as those with sporadic or dominantly inhierited olivoponto‐cerebellar atrophy as compared with normal control subjects. The finding of relative preservation of benzodiazepine receptors indicates that these sites are available for pharmacological therapy in these disorders.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92122/1/410380209_ftp.pd

Patterns of cerebral glucose metabolism detected with positron emission tomography differ in multiple system atrophy and olivopontocerebellar atrophy

We used positron emission tomography with [ 18 F] fluorodeoxyglucose to study local cerebral metabolic rates for glucose (ICMRglc) in patients with multiple system atrophy (MSA), sporadic olivopontocerebellar atrophy (sOPCA), and dominantly inherited olivopontocerebellar atrophy (dOPCA) in comparison with normal control subjects. In MSA, absolute lCMRglc was significantly decreased in the brainstem, cerebellum, putamen, thalamus, and cerebral cortex. In sOPCA, absolute lCMRglc was significantly decreased in the brainstem, cerebellum, putamen, thalamus, and cerebral cortex. In dOPCA, absolute lCMRglc was significantly decreased in the brainstem and cerebellum but not in the other structures. Examination of lCMRglc normalized to the cerebral cortex in comparison with normal controls revealed in MSA significant decreases in the brainstem, cerebellum, and putamen but, in both sOPCA and dOPCA, significant decreases only in the brainstem and cerebellum. The findings indicate that these three disorders all show a marked decrease of lCMRglc in the brainstem and cerebellum but differ in the degree of hypometabolism in forebrain and cerebral cortical structures. The results are consistent with the possibility that, in many cases, sOPCA will evolve into MSA. Moreover, positron emission tomography may provide helpful diagnostic information in these neurodegenerative diseases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50356/1/410360208_ftp.pd

Can MR Imaging Diagnose Adult-Onset Alexander Disease?

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A transient third cranial nerve palsy as presenting sign of spontaneous intracranial hypotension

Spontaneous intracranial hypotension is an uncommon cause of sudden and persistent headache: associated symptoms are common, among which there are cranial nerve palsies, especially of the abducens nerve. We report a case of a 21-year-old man with a transient and isolated third nerve palsy due to spontaneous intracranial hypotension. To our knowledge, there are only few reports in the literature of such association

New MR sequences in daily practice: susceptibility weighted imaging. A pictorial essay

Background Susceptibility-weighted imaging (SWI) is a relatively new magnetic resonance (MR) technique that exploits the magnetic susceptibility differences of various tissues, such as blood, iron and calcification, as a new source of contrast enhancement. This pictorial review is aimed at illustrating and discussing its main clinical applications. Methods SWI is based on high-resolution, threedimensional (3D), fully velocity-compensated gradientecho sequences using both magnitude and phase images. A phase mask obtained from the MR phase images is multiplied with magnitude images in order to increase the visualisation of the smaller veins and other sources of susceptibility effects, which are displayed at best after postprocessing of the 3D dataset with the minimal intensity projection (minIP) algorithm. Results SWI is very useful in detecting cerebral microbleeds in ageing and occult low-flow vascular malformations, in characterising brain tumours and degenerative diseases of the brain, and in recognizing calcifications in various pathological conditions. The phase images are especially useful in differentiating between paramagnetic susceptibility effects of blood and diamagnetic effects of calcium. SWI can also be used to evaluate changes in iron content in different neurodegenerative disorders. Conclusion SWI is useful in differentiating and characterising diverse brain disorders

Adult-onset Alexander disease, associated with a mutation in an alternative GFAP transcript, may be phenotypically modulated by a non-neutral HDAC6 variant

Background: We studied a family including two half-siblings, sharing the same mother, affected by slowly progressive, adult-onset neurological syndromes. In spite of the diversity of the clinical features, characterized by a mild movement disorder with cognitive impairment in the elder patient, and severe motor-neuron disease (MND) in her half-brother, the brain Magnetic Resonance Imaging (MRI) features were compatible with adult-onset Alexander's disease (AOAD), suggesting different expression of the same, genetically determined, condition. Methods. Since mutations in the alpha isoform of glial fibrillary acidic protein, GFAP-\uce\ub1, the only cause so far known of AOAD, were excluded, we applied exome Next Generation Sequencing (NGS) to identify gene variants, which were then functionally validated by molecular characterization of recombinant and patient-derived cells. Results: Exome-NGS revealed a mutation in a previously neglected GFAP isoform, GFAP-, which disrupts the GFAP-associated filamentous cytoskeletal meshwork of astrocytoma cells. To shed light on the different clinical features in the two patients, we sought for variants in other genes. The male patient had a mutation, absent in his half-sister, in X-linked histone deacetylase 6, a candidate MND susceptibility gene. Conclusions: Exome-NGS is an unbiased approach that not only helps identify new disease genes, but may also contribute to elucidate phenotypic expression. \uc2\ua9 2013 Melchionda et al