Intraoperative Neuromonitoring of the Visual Pathway in Asleep Neuro-Oncology Surgery.

Brain tumour surgery in visual eloquent areas poses significant challenges to neurosurgeons and has reported inconsistent results. This is a single-centre prospective cohort study of patients admitted for asleep surgery of intra-axial lesions in visual eloquent areas. Demographic and clinical information, data from tractography and visual evoked potentials (VEPs) monitoring were recorded and correlated with visual outcomes. Thirty-nine patients were included (20 females, 19 males; mean age 52.51 ± 14.08 years). Diffuse intrinsic glioma was noted in 61.54% of patients. There was even distribution between the temporal, occipital and parietal lobes, while 55.26% were right hemispheric lesions. Postoperatively, 74.4% remained stable in terms of visual function, 23.1% deteriorated and 2.6% improved. The tumour infiltration of the optic radiation on tractography was significantly related to the visual field deficit after surgery (p = 0.016). Higher N75 (p = 0.036) and P100 (p = 0.023) amplitudes at closure on direct cortical VEP recordings were associated with no new postoperative visual deficit. A threshold of 40% deterioration of the N75 (p = 0.035) and P100 (p = 0.020) amplitudes correlated with a risk of visual field deterioration. To conclude, direct cortical VEP recordings demonstrated a strong correlation with visual outcomes, contrary to transcranial recordings. Invasion of the optic radiation is related to worse visual field outcomes.

Short-lasting retroorbital pain attacks as a form of ictal epileptic headache: Case report.

BACKGROUND AND OBJECTIVES: Ictal epileptic headache is a rare form of painful seizure, habitually consisting of migrainous or tension-type headache. We describe a case of a patient with short-lasting, severe retroorbital pain attacks caused by frontal lobe epilepsy. CASE REPORT: A 25-year-old male patient presented with recurrent attacks of paroxysmal, short-lasting, excruciating left periorbital and facial pain mainly occurring from sleep. After intracranial EEG exploration and resection of a right prefrontal focal cortical dysplasia, long-term seizure and headache remission was obtained. DISCUSSION: Our case extends the clinical and neuroanatomical spectrum of ictal epileptic headache and suggests that long-term remission can be obtained by resective epilepsy surgery. It also reinforces the role of the prefrontal cortex in the pain matrix and pain generation. CONCLUSION: Despite its rarity, ictal epileptic headache should be suspected in selected patients, particularly those with other ictal symptoms and signs, history of epileptic seizures, or neuroimaging abnormalities.

A new MRI rating scale for progressive supranuclear palsy and multiple system atrophy: validity and reliability.

AIM: To evaluate a standardised MRI acquisition protocol and a new image rating scale for disease severity in patients with progressive supranuclear palsy (PSP) and multiple systems atrophy (MSA) in a large multicentre study. METHODS: The MRI protocol consisted of two-dimensional sagittal and axial T1, axial PD, and axial and coronal T2 weighted acquisitions. The 32 item ordinal scale evaluated abnormalities within the basal ganglia and posterior fossa, blind to diagnosis. Among 760 patients in the study population (PSP = 362, MSA = 398), 627 had per protocol images (PSP = 297, MSA = 330). Intra-rater (n = 60) and inter-rater (n = 555) reliability were assessed through Cohen's statistic, and scale structure through principal component analysis (PCA) (n = 441). Internal consistency and reliability were checked. Discriminant and predictive validity of extracted factors and total scores were tested for disease severity as per clinical diagnosis. RESULTS: Intra-rater and inter-rater reliability were acceptable for 25 (78%) of the items scored (≥ 0.41). PCA revealed four meaningful clusters of covarying parameters (factor (F) F1: brainstem and cerebellum; F2: midbrain; F3: putamen; F4: other basal ganglia) with good to excellent internal consistency (Cronbach α 0.75-0.93) and moderate to excellent reliability (intraclass coefficient: F1: 0.92; F2: 0.79; F3: 0.71; F4: 0.49). The total score significantly discriminated for disease severity or diagnosis; factorial scores differentially discriminated for disease severity according to diagnosis (PSP: F1-F2; MSA: F2-F3). The total score was significantly related to survival in PSP (p<0.0007) or MSA (p<0.0005), indicating good predictive validity. CONCLUSIONS: The scale is suitable for use in the context of multicentre studies and can reliably and consistently measure MRI abnormalities in PSP and MSA. Clinical Trial Registration Number The study protocol was filed in the open clinical trial registry (http://www.clinicaltrials.gov) with ID No NCT00211224.

CT/MR image fusion in the postoperative assessment of electrodes implanted for deep brain stimulation.

BACKGROUND/AIMS: Stereotactic postoperative imaging is essential for verification of the position of electrodes implanted for deep brain stimulation (DBS). MRI offers superior visualisation of the DBS targets relative to CT, but previous adverse incidents have heightened concerns about risks of postoperative MRI. Preoperative MRI fused with postoperative CT offers an alternative method for evaluating electrode position, but before this method can be clinically applied, the image registration accuracy must be established. The purpose of this study was to quantitatively assess the accuracy of three different image registration and fusion methods. METHODS: Preoperative stereotactic MRI and postoperative stereotactic CT were acquired from 20 patients under- going DBS surgery (35 electrodes in total). The postoperative CT was registered and fused with the preoperative MRI, using three different registration algorithms. The position of each electrode tip was determined in stereotactic coordinates both in the (unfused) postoperative CT and the fused CT/MRI. The difference in tip position between the CT and fused CT/MRI was used to evaluate the registration accuracy. RESULTS: The mean error along the lateral, anteroposterior, and vertical axes was 0.5, 0.5, and 1 mm, respectively. CONCLUSIONS: CT/MRI fusion provides a safe, practical technique for postoperative identification of DBS electrodes.

The clinical spectrum of epilepsy in children and adults with hypothalamic hamartoma.

PURPOSE: Hamartomas of the hypothalamus (HH) cause an uncommon and unusual epilepsy syndrome. The condition is recognized to affect children, but the presentation in adults is not well understood. We present 19 children and adult patients with HH, including three patients whose epilepsy began in adult life. The patterns of clinical presentation, evolution of the epilepsy from childhood to adult life, and electroclinical diagnostic features are presented. METHODS: Nineteen patients, both children and adults with HH and epilepsy, were evaluated clinically, with EEG, video-EEG, and magnetic resonance imaging (MRI) scanning. Seven patients underwent surgical resection of the hamartoma. Stereotactic thermocoagulation of the hamartoma was performed in two patients. RESULTS: Gelastic seizures occurred at onset of epilepsy in 15 of 16 early-onset cases. Subsequently, multiple seizures types occurred, which then evolved to mainly partial epilepsy with tonic or complex partial seizures (five of eight adults), or became entrenched symptomatic generalized epilepsy with atypical absences, drop attacks, and secondarily generalized seizures, and cognitive impairment (three of eight adults). In the adult-onset patients, gelastic seizures were not prominent, the epilepsy was milder, and they functioned normally. Stereotactic thermocoagulation of the hamartoma resulted in improvement in seizure control in two patients. CONCLUSIONS: Gelastic seizures are not a prominent feature of epilepsy in adult patients with HH. The epilepsy associated with HH, although severe at onset, can evolve into a milder syndrome in later life. For less severely affected patients, minimally invasive alternatives to the traditionally difficult open surgical treatment should be considered.