News Briefs From the 65th Annual Meeting of the American Academy of Neurology

Karnofsky scores lower than 50 indicate that the patient may not be able to care for himself or herself and may require institutional care. A Karnofsky score of 70 suggests that the person can care for himself or herself, but may not be able to engage in normal activities or work. A Karnofsky score of 50 indicates that a person may require considerable assistance and frequent medical care.

As of January 1, 2013, all 21 participants with no symptoms at the time of PML diagnosis were alive, compared with 77% of those with symptoms at the time of diagnosis. "These results suggest that the consequences of PML infection can be mitigated by early detection of the disease," said Dr. Dong-Si.

CT Perfusion May Help Distinguish Between Stroke and Seizure
CT perfusion scans may help neurologists distinguish between acute stroke and seizures, according to data reported at the 65th Annual Meeting of the American Academy of Neurology. The technique may thus prevent the improper use of t-PA and subsequent hemorrhagic complications.

Neeta Duggal, MD, from the University of Missouri in Kansas City, and colleagues presented a case study of a man, age 75, with a history of hypertension and hyperlipidemia who presented to the emergency room with gaze deviation, right-sided weakness, and speech difficulties.

The man's NIH Stroke Scale score was 12, and he had not had any witnessed seizures. The time of symptom onset was approximately three hours before presentation. A CT scan of the man's head without contrast did not show acute changes. After conducting a CT perfusion study, the neurologists observed hyperperfusion in the left parieto–occipital region with low blood volume. After returning from the scan, the patient developed a witnessed seizure and was treated with IV levetiracetam and lacosamide.

The neurologists later performed an EEG that revealed left-sided spike activity. An MRI of the head showed old encephalomalacia in the left parieto–occipital lobe. The patient ultimately had resolution of the hemiparesis and speech abnormalities.

"Our study demonstrates that CT perfusion scans are helpful in differentiating seizures from acute strokes based on the patterns of blood flow, blood volume, and mean transit time seen on the scans," said Dr. Duggal. Increased cerebral blood flow in a CT perfusion study indicates a seizure, while decreased blood flow indicates an ischemic event, she added. An EEG, which is more time consuming than CT perfusion, can be performed later to confirm seizure activity.

Can CSF Biomarkers Quicken the Diagnosis of Frontotemporal Lobar Degeneration?
CSF biomarkers could help neurologists accurately identify frontotemporal lobar degeneration with lesions immunoreactive to TDP-43 (FTLD-TDP), according to research presented at the 65th Annual Meeting of the American Academy of Neurology. Neurologists previously had no way to predict the underlying FTLD pathology while the patients were still alive. Further development of FTLD-TDP biomarkers has the potential to significantly accelerate the ante-mortem prediction of FTLD-TDP pathology and the design of substrate-specific FTLD clinical trials.

To validate five previously identified CSF biomarkers for FTLD-TDP and investigate a novel CSF biomarker for the disease, William Hu, MD, PhD, Cognitive Neurologist at Emory University School of Medicine in Atlanta, and colleagues recruited two independent cohorts of patients with frontotemporal dementia (FTD) from Emory University and the University of Pennsylvania to undergo CSF analysis.

The cohorts included patients with highly probable FTLD-TDP (ie, patients with FTD and amyotrophic lateral sclerosis or patients with FTD and mutations in PGRN or C9ORF72) and patients with highly probable FTLD-tau (ie, patients with FTD and progressive supranuclear palsy or FTD patients with mutations in MAPT).

The investigators measured levels of five previously identified CSF proteins, along with levels of total tau (t-tau) and tau phosphorylated at threonine 181 (p-tau181).

A total of 29 patients from Emory University and 40 patients from the University of Pennsylvania participated in the study. Of the total population, 43 patients had highly probable FTLD-TDP and 26 patients had highly probable FTLD-tau. Using the Emory cohort, the researchers validated the group-level differences in CSF eotaxin-3, Fas, and IL-23 previously identified using the University of Pennsylvania cohort. The group also concluded that the ratio of p-tau181 to t-tau (ie, the p/t-tau ratio) was significantly lower in patients with FTLD-TDP recruited at Emory, compared with patients with FTLD-tau and Alzheimer's disease recruited at Emory.

"Using the Pennsylvania cohort as a validation set, p/t-tau ratio alone is sufficient to identify FTLD-TDP with 88% sensitivity and 73% specificity," said Dr. Hu.