A Crossed Pure Agraphia by Graphemic Buffer Impairment following Right Orbito-Frontal Glioma Resection.

Pure agraphias are caused by graphemic buffer damage. The graphemic buffer stores graphemic representations that handle the transition from spelling lexicon to writing or oral spellings. The authors report a case of a crossed pure agraphia, following the post-surgical removal of a right frontal low-grade glioma in a right-handed French patient. He presented a pure agraphia displaying the features of a graphemic buffer impairment. Our patient only made spelling errors, whereas repetition and other oral language abilities remained perfect. We found a greater number of errors for longer stimuli, increased errors for the medially located graphemes, and agraphia for both words and non-words and error types, essentially consisting of omissions, substitutions, and letter transpositions. We also observed no significant effect of word frequency on spelling errors, but word length affected the rate of errors. The particularity of this case was linked to right frontal subcortical injuries in a right-handed subject. To our knowledge, it is the first report of a crossed pure agraphia caused by graphemic buffer impairment. Further studies are needed in order to analyse the role of subcortical structures, particularly the caudate nucleus in the graphemic buffer during writing tasks, as well as the participation of the non-dominant hemisphere in writing language.

Designing an operating theatre for awake procedures: A solution to improve multimodality information input.

OBJECTIVE: Many neurosurgical procedures are now performed with the patient aware in order to allow interactions between the patient and healthcare professionals. These procedures include awake brain surgery and spinal cord stimulation (SCS), lead placement for treatment of refractory chronic back and leg pain. Neurosurgical procedures under local anaesthesia require optimal intraoperative cooperation of the patient and all personnel involved in surgery. In addition to accommodating this extra source of intraoperative information all other necessary sources of data relevant to the procedure must be presented. The concept of an operating room dedicated to neurosurgical procedures performed aware and accommodating these concepts is presented, and some evidence for improvements in outcome presented, deriving from a series of patients implanted with spinal cord stimulators before and after the operating theatre was brought into service. RESULTS AND DISCUSSION: In addition to the description, two videos demonstrate the facility online. Beyond this qualitative evidence, quantitative improvement in patient outcome is evidenced by the series presented: 91.3% of patients operated in the awake anaesthesia-dedicated theatre obtained adequate low back pain coverage, versus 60.0% for patients operated before (p = 0.028). CONCLUSION: The concept of such an operating room is a step in improving the outcome by improving the presentation of all types of information to the operating room staff most notably in the example of aware procedures.

Apathy in Parkinson's disease: an electrophysiological study.

In Parkinson's disease (PD), apathy (or loss of motivation) is frequent. Nevertheless, the contribution of attentional disorders to its genesis is still not clearly known. We want to determine the relation existing between apathy and attentional disorders by using P300a (or novelty P3) as a marker of the attentional process. The study included 25 patients (13 women and 12 men) with PD for whom we have determined the relationship between automatic attention (represented by P300a) and motor status, apathy, executive dysfunction, mental flexibility, inhibitory control, and depression/anxiety. We have found a correlation between the apathy score and amplitude of novelty P300 during the ON period and also a correlation of the apathy score with a decrease in amplitude of P300 during the OFF period. In a linear regression model, changes in the P300a predicted the severity of apathy independently of any other variable. We concluded firstly that the reduction in amplitude of the P300a wave was a neurophysiological marker of apathy in PD and secondly that apathy led to both dopaminergic denervation (mesolimbic) and nondopaminergic (dorsolateral prefrontal-subcortical) dysfunction.

Intraoperative monitoring of an aspect of executive functions: administration of the Stroop test in 9 adult patients during awake surgery for resection of frontal glioma.

BACKGROUND: Awake brain surgery allows extensive intraoperative monitoring of not only motor and sensory functions and language but also executive functions. OBJECTIVE: To administer the Stroop test intraoperatively to avoid dramatic side effects such as akinetic mutism and to monitor executive functions in an attempt to optimize the benefit/risk balance of surgery. METHODS: A series of 9 adult patients with frontal glioma were operated on for gross tumor resection under local anesthesia. All procedures involved the anterior cingulate cortex (ACC). RESULTS: Three types of response to the Stroop test were observed: 3 patients had a Stroop effect only for stimulation of the contralateral ACC; 3 patients had a Stroop effect for stimulation of the ipsilateral ACC; and 3 patients had no Stroop effect. Preoperative and postoperative neuropsychological and surgical results are presented and discussed. Stimulation sites eliciting a Stroop effect are compared with published image-based data, and insight provided by these surgical data regarding ACC function and plasticity is discussed. No operative complication related to intraoperative administration of the Stroop test was observed. CONCLUSION: Administration of the Stroop test during resection of gliomas involving the ACC in adult patients is an option for intraoperative monitoring of executive functions during awake surgery. Globally, these results suggest functional compensation, mediated by plasticity mechanisms, by contralateral homologous regions of the ACC in adult patients with frontal glioma.

Peripheral p70S6k levels and emotional memory in patients with Alzheimer's disease.

Alzheimer's disease (AD) is clinically marked at the onset, by memory disturbances affecting explicit memory. Emotional explicit memory is enhanced in normal subjects and remained less affected at the beginning of AD. The kinase p70S6k participates in the control of protein translation and seems also implicated in the process of synaptic plasticity and the formation of memory at the molecular level. In a previous study, we have shown that peripheral p70S6k level is correlated with the decline of cognitive and memory functions in patients with AD. The goal of the present study was to analyse emotional and neutral explicit memory in AD patients and to evaluate the levels of active p70S6k in lymphocytes by western blots. The results reveal that the difference between emotional and neutral memories are correlated with the levels of peripheral p70S6k in patients with AD, as well as with the global cognitive scores assessed by the Mini Mental Status Examination. The decline of emotional memory in AD patients is reflected by the decrease of p70S6k levels.

Activated mTOR and PKR kinases in lymphocytes correlate with memory and cognitive decline in Alzheimer's disease.

BACKGROUND: The control of translation, involving the kinases mTOR (mammalian target of rapamycin) and PKR (double-stranded RNA-dependent protein kinase), modulates cell survival and death and is altered in the brains of patients with Alzheimer's disease (AD). In AD increased susceptibility of lymphocytes to apoptosis has been reported. METHODS: We investigated the level of the kinases mTOR and PKR and the eukaryotic initiation factor 2alpha (eIF2alpha) in lymphocytes of patients with AD in comparison with controls. In AD patients we also looked for a correlation between activated proteins and cognitive and memory tests. RESULTS: We report significant alterations of the levels of these kinases and eIF2alpha in lymphocytes of AD patients that were also significantly correlated with cognitive and memory test scores. CONCLUSION: These results suggest that the levels of mTOR, PKR and eIF2alpha in lymphocytes could follow the cognitive decline in AD.