Shamik Bhattacharyya

Antibiotic-associated encephalopathy.

Delirium is a common and costly complication of hospitalization. Although medications are a known cause of delirium, antibiotics are an underrecognized class of medications associated with delirium. In this article, we comprehensively review the clinical, radiologic, and electrophysiologic features of antibiotic-associated encephalopathy (AAE). AAE can be divided into 3 unique clinical phenotypes: encephalopathy commonly accompanied by seizures or myoclonus arising within days after antibiotic administration (caused by cephalosporins and penicillin); encephalopathy characterized by psychosis arising within days of antibiotic administration (caused by quinolones, macrolides, and procaine penicillin); and encephalopathy accompanied by cerebellar signs and MRI abnormalities emerging weeks after initiation of antibiotics (caused by metronidazole). We correlate these 3 clinical phenotypes with underlying pathophysiologic mechanisms of antibiotic neurotoxicity. Familiarity with these types of antibiotic toxicity can improve timely diagnosis of AAE and prompt antibiotic discontinuation, reducing the time patients spend in the delirious state.

Emerging Cases of Powassan Virus Encephalitis in New England: Clinical Presentation, Imaging, and Review of the Literature

BACKGROUND Powassan virus (POWV) is a rarely diagnosed cause of encephalitis in the United States. In the Northeast, it is transmitted by Ixodes scapularis, the same vector that transmits Lyme disease. The prevalence of POWV among animal hosts and vectors has been increasing. We present 8 cases of POWV encephalitis from Massachusetts and New Hampshire in 2013-2015. METHODS We abstracted clinical and epidemiological information for patients with POWV encephalitis diagnosed at 2 hospitals in Massachusetts from 2013 to 2015. We compared their brain imaging with those in published findings from Powassan and other viral encephalitides. RESULTS The patients ranged in age from 21 to 82 years, were, for the most part, previously healthy, and presented with syndromes of fever, headache, and altered consciousness. Infections occurred from May to September and were often associated with known tick exposures. In all patients, cerebrospinal fluid analyses showed pleocytosis with elevated protein. In 7 of 8 patients, brain magnetic resonance imaging demonstrated deep foci of increased T2/fluid-attenuation inversion recovery signal intensity. CONCLUSIONS We describe 8 cases of POWV encephalitis in Massachusetts and New Hampshire in 2013-2015. Prior to this, there had been only 2 cases of POWV encephalitis identified in Massachusetts. These cases may represent emergence of this virus in a region where its vector, I. scapularis, is known to be prevalent or may represent the emerging diagnosis of an underappreciated pathogen. We recommend testing for POWV in patients who present with encephalitis in the spring to fall in New England.

Oral Inosine Persistently Elevates Plasma antioxidant capacity in Parkinson's disease

Higher serum urate predicts slower progression in PD. The aim of this work was to assess whether oral inosine alters antioxidant capacity of plasma or CSF or urinary markers of oxidative injury in early PD.

Neurologic complications of systemic lupus erythematosus, sjögren syndrome, and rheumatoid arthritis.

Neurologic complications are frequent and often morbid in systemic lupus erythematosus, Sjögren syndrome, and rheumatoid arthritis. Although all are systemic inflammatory syndromes, each disease affects the nervous system distinctly, such as peripheral neuropathy in Sjögren syndrome, cerebrovascular disease in lupus, and cervical spine subluxation in rheumatoid arthritis. Some neurologic complications share convergent pathophysiology across diseases, such as neuromyelitis optica spectrum disorders in both Sjögren syndrome and lupus. Ill-defined cognitive complaints are especially common in lupus and Sjögren syndrome. For the majority of the complications, evidence for treatment efficacy is limited and requires further investigation.

Primary angiitis of the central nervous system: avoiding misdiagnosis and missed diagnosis of a rare disease

Primary angiitis of the central nervous system (PACNS) is an extremely rare condition, defined as a vasculitis limited to the CNS with no identifiable cause. Its presentation is non-specific and includes headache, cognitive dysfunction and focal neurological signs. Laboratory studies, neuroimaging and angiography are neither sufficiently sensitive nor specific for diagnosis; a definitive diagnosis requires brain biopsy. As a result, PACNS is commonly misdiagnosed. Here, we review its clinical, laboratory and radiological features, and focus on avoiding common diagnostic pitfalls.

Antibiotic-Induced Neurotoxicity

Antibiotic neurotoxicity is rare but can cause significant morbidity when it occurs. The risk of antibiotic neurotoxicity appears to be highest in patients who are older, have impaired renal function, or have preexisting neurologic conditions. This review describes the clinical features of the most common antibiotic toxicities affecting the nervous system: seizures, encephalopathy, optic neuropathy, peripheral neuropathy, and exacerbation of myasthenia gravis.

Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct

The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

Bilateral Hippocampal Restricted Diffusion: Same Picture Many Causes

With some regularity, we have encountered the unusual imaging abnormality of bilateral hippocampal restricted diffusion, either in isolation or in combination with other coincident abnormalities. In this retrospective case series, we examine clinical and imaging data to explore potential etiologies and clinical implications of this imaging finding. Sixteen cases with the imaging abnormality are presented, with etiologies including hypoxemia, hypoxemia‐ischemia, and seizures.

Antibiotic-associated encephalopathyAuthor Response

Bhattacharyya et al. described a type II antibiotic-associated encephalopathy (AAE) where macrolides, among others, were involved.1 The authors suggested that “type 2 AAE closely resemble[d] drug-induced psychotic syndromes caused by perturbations of the D2 dopamine and NMDA glutamate receptors.”1 Where was the evidence of such a mechanism found? Additionally, penetration of clarithromycin into the CSF and brain tissue of a healthy animal is relatively low or absent. It is only when …

Cervical spine fracture associated with ankylosing spondylitis

A 53-year-old man with ankylosing spondylitis (AS) was found unresponsive on the ground. He was comatose and quadriplegic with absent cough and gag reflexes but preserved corneal and pupillary responses. CT of the spine (figure) showed displaced C2 fracture, severely deformed spinal cord, and complete spinal ankylosis. He developed hemodynamic instability with persistently poor arousal, and his family elected to withdraw care. AS, chronic inflammatory disease of the axial skeleton, results in ossified ligaments and loss of elasticity, predisposing to spinal fractures following minor trauma. Three-quarters of these fractures occur in the cervical spine, with associated mortality rate of 35%.1