Delayed post-anoxic encephalopathy

Prediction of good neurological outcome in comatose survivors of cardiac arrest: a systematic review

PURPOSE

To assess the ability of clinical examination, blood biomarkers, electrophysiology or neuroimaging assessed within 7 days from return of spontaneous circulation (ROSC) to predict good neurological outcome, defined as no, mild, or moderate disability (CPC 1-2 or mRS 0-3) at discharge from intensive care unit or later, in comatose adult survivors from cardiac arrest (CA).

METHODS

PubMed, EMBASE, Web of Science and the Cochrane Database of Systematic Reviews were searched. Sensitivity and specificity for good outcome were calculated for each predictor. The risk of bias was assessed using the QUIPS tool.

RESULTS

A total of 37 studies were included. Due to heterogeneities in recording times, predictor thresholds, and definition of some predictors, meta-analysis was not performed. A withdrawal or localisation motor response to pain immediately or at 72-96 h after ROSC, normal blood values of neuron-specific enolase (NSE) at 24 h-72 h after ROSC, a short-latency somatosensory evoked potentials (SSEPs) N20 wave amplitude > 4 µV or a continuous background without discharges on electroencephalogram (EEG) within 72 h from ROSC, and absent diffusion restriction in the cortex or deep grey matter on MRI on days 2-7 after ROSC predicted good neurological outcome with more than 80% specificity and a sensitivity above 40% in most studies. Most studies had moderate or high risk of bias.

CONCLUSIONS

In comatose cardiac arrest survivors, clinical, biomarker, electrophysiology, and imaging studies identified patients destined to a good neurological outcome with high specificity within the first week after cardiac arrest (CA).

HD-tDCS as a neurorehabilitation technique for a case of post-anoxic leukoencephalopathy

Post-anoxic leukoencephalopathy is a rare event that causes global demyelination secondary to anoxic injury. Given the nature and extent of the damage, cognitive and functional deficits are typically chronic even after standard therapies. Here, we describe a novel treatment approach that used high definition transcranial direct-current stimulation (HD-tDCS) with a 62-year-old male who was 5 years post-anoxic leukoencephalopathy secondary to an accidental drug overdose. HD-tDCS was administered over the left lateral prefrontal cortex across 29 daily sessions at 2 mA (20 min/session) in order to address dysexecutive behaviors. Results demonstrated improved delayed memory and trends for improved visuospatial and semantic fluency performance as well as improved insight and daily functioning, all of which returned to baseline by the end of a 10 week no-contact follow up period. Resting state fMRI connectivity results mirrored these changes by showing increased dorsal attention and cingulo-opercular but reduced ventral attention network connectivity after session 29, all of which returned to baseline at follow-up. These findings suggest HD-tDCS may benefit functioning even following serious and pervasive anoxic injury. Findings also suggest the need for continued HD-tDCS for maintenance purposes, though future work is needed to identify optimal dose-response information.

Temporary recovery after resuscitation: delayed postanoxic encephalopathy

Delayed postanoxic encephalopathy is reported infrequently and is characterised by a lucid interval of seemingly good recovery from an anoxic insult. Days or even weeks may pass before changes in behaviour, motor responses or consciousness occur. Neurological deterioration may progress to coma, death or severe disability, whereas some patients have a second recovery period. Pathogenesis is yet to be discovered. Prognosis is reportedly poor, treatment is symptomatic and at best anecdotal. We present a case report and available literature.

Delayed postanoxic encephalopathy: a case report and literature review

Delayed postanoxic encephalopathy is a rare condition in which patients appear to make a complete clinical recovery after an episode of anoxia or hypoxia but then develop a relapse characterized by apathy, confusion, agitation, and/or progressive neurologic deficits. The incidence of delayed postanoxic encephalopathy is unclear but has been reported to range from less than 1 to 28 per 1000 in patients who have suffered hypoxic or anoxic events. The exact pathogenesis remains unknown. We describe a case of an independently living 51-year-old woman admitted to an inpatient rehabilitation unit 11 days after a respiratory arrest. At admission, she exhibited cognitive and visual deficits that were relatively mild but prevented a safe return to independent living. Two days later, she developed the sudden onset and rapid worsening of parkinsonian symptoms and excruciating bilateral lower-extremity pain. The pain was intractable, and over the next 2 days she progressed to being unable to walk or perform her activities of daily living without maximum assistance. A diagnosis of delayed postanoxic encephalopathy was made, and the patient responded to a trial of carbidopa and levodopa as well as redirection of her physical and occupational therapy programs. This case illustrates the unusual presentation of delayed postanoxic encephalopathy during inpatient rehabilitation and suggests that this condition should be considered if patients who have suffered an anoxic or hypoxic event show a sudden neurologic deterioration.

Irreversible Subcortical Dementia Following High Altitude Illness

In this report, we present the cases of two 63-year-old women who developed high altitude cerebral edema complicated by the occurrence of permanent neuropsychiatric sequelae. They shared a similar clinical course, in that both developed disturbance of consciousness shortly after their arrival at Cuzco, Peru (3500 m), and both developed persistent neuropsychiatric symptoms after resolution of the acute illness. Interestingly, in case 2 there was a 1-month lucid interval between remission of high altitude illness and occurrence of the irreversible neuropsychiatric sequelae. Brain computerized tomography in case 1 and brain magnetic resonance imaging in case 2 disclosed lesions in the globus pallidus bilaterally, suggesting that the neuropsychiatric symptoms in these patients were manifestations of subcortical dementia. The development of high altitude illness was considered to be attributable to mild restrictive lung impairment in case 1 and to a deficient ventilatory response to hypoxia in case 2. It must therefore be borne in mind that irreversible subcortical dementia may be associated with high altitude cerebral edema.