Subthalamic Nucleus Deep Brain Stimulation for Parkinson Disease in Hong Kong: A Prospective Territory-Wide 2-Year Follow-Up Study.

OBJECTIVE: We assessed the effects of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with Parkinson disease at the 1-year and 2-year follow-up evaluations. Unified Parkinson's Disease Rating Scale (UPDRS) motor score at "off" medication ("on" DBS) and quality-of-life assessments (39-item Parkinson's Disease Questionnaire [PDQ-39]) were conducted. The percentage of awake "on" time and awake "off" time and levodopa requirement were also assessed. METHODS: A 2-year prospective study was conducted of 25 consecutive patients from 3 DBS referral centers in Hong Kong. The patients were treated with bilateral stimulation of the STN. Assessments were performed at 1 year and 2 years after DBS and were compared with the baseline. RESULTS: The 2-year outcome assessments were completed by 18 patients. The mean UPDRS motor score improvement was 57% in the first year and 45% in the second year. PDQ-39 showed significant improvement in quality of life for 2 consecutive years. The levodopa requirement decreased 63% in the first year and 55.9% in the second year. The awake "on" time was doubled in the first year and sustained in the second year. Awake "off" time was reduced from 28.1% to 5.9% in the first year and returned to 10.6% in the second year. Improvement of UPDRS motor score, reduction in awake "off" time, and decrease of daily levodopa dosage all were main factors correlated with the improvement in PDQ-39 summary index. CONCLUSIONS: The effects of STN DBS in patients with Parkinson disease in Hong Kong were satisfactory. The results showed that reduction in UPDRS motor score, awake "off"-time, and daily levodopa dosage were the major drivers of overall improvement in PDQ-39.

Ictal high-frequency oscillations and hyperexcitability in refractory epilepsy.

OBJECTIVE: High-frequency oscillations (HFOs, 80-500Hz) from intracranial electroencephalography (EEG) may represent a biomarker of epileptogenicity for epilepsy. We explored the relationship between ictal HFOs and hyperexcitability with a view to improving surgical outcome. METHODS: We evaluated 262 patients with refractory epilepsy. Fifteen patients underwent electrode implantation, and surgical resection was performed in 12 patients using a semi-prospective design. Ictal intracranial EEGs were examined by continuous wavelet transform (CWT). Significant ictal HFOs were denoted by normalized wavelet power above the 50th percentile across all channels. Each patient underwent functional mapping with cortical electrical stimulation. Hyperexcitability was defined as the appearance of afterdischarges or clinical seizures after electrical stimulation (50Hz, biphasic, pulse width=0.5ms, 5s, 5mA). RESULTS: Among the group of patients achieving Engel Class I/II outcome at 1+ year, the mean proportion of significant ictal HFOs among resected channels for any given patient was 69% (33.3-100%). The respective figures for conventional frequency ictal patterns (CFIPs), hyperexcitability, and radiological lesion were 68.3% (26.3-100%), 39.6% (0-100%), and 52.8% (0-100%). Statistical significance was only achieved with ictal HFOs when comparing patients with Engel Class I/II outcomes versus III/IV outcomes (12.6% vs. 4.2%, the number of channels as the denominator, p=0.005). Further analysis from all patients irrespective of the surgical outcome showed that ictal HFOs co-occurred with CFIP (p<0.001), hyperexcitability (p<0.001), and radiological lesion (p<0.001). The combination of ictal HFOs/hyperexcitability improved the sensitivity from 66.7% to 100%, and the specificity from 66.7% to 75% when compared with ictal HFOs or hyperexcitability alone. CONCLUSIONS: We confirmed the utility of ictal HFOs in determining surgical outcome. Ictal HFOs are affiliated to cortical hyperexcitability, which may represent a pathological manifestation of epileptogenicity. SIGNIFICANCE: Presurgical evaluation of refractory epilepsy may incorporate both ictal HFOs and cortical stimulation in determining epileptogenic foci.

Evidence of improved immediate verbal memory and diminished category fluency following STN-DBS in Chinese-Cantonese patients with idiopathic Parkinson's disease.

The present study investigated the neuropsychological effects of bilateral deep brain stimulation (DBS) on subthalamic nucleus (STN) in Chinese-Cantonese patients with idiopathic Parkinson's disease (PD). Twenty-seven patients were prospectively recruited from the Movement Disorder Clinic at the Hong Kong Prince of Wales Hospital. Neuropsychological evaluations were performed at baseline, 6 and 12 months following the DBS procedure. Assessment battery included standardized tests on global cognitive function, verbal memory, non-verbal memory, confrontation naming, visuospatial organization, attention and executive functions. Anxiety and depressive symptoms were measured by two self-reported questionnaires. Results demonstrated diminished performance on a category fluency task that occurred at 6 months post-operatively and persisted at 12-month re-evaluation; 29.6-33.3 % of patients showed reduction of more than 1 SD (standard deviation) at post-operative measure. Conversely, performance on an immediate recall task in a verbal memory test was found to improve significantly at the same time point and persisted through 12 months after surgery; 22.2-25.9 % showed an improvement (≥1 SD). Psychologically, anxiety symptoms were statistically decreased and the significant reduction occurred at 12 months after surgery. Patients who reported a moderate to severe level of anxiety reduced from 51.9 to 18.5 %. Our findings concurred with most evidences on the effects of STN-DBS on verbal fluency; on the other hand, we demonstrated improvement of immediate verbal memory that warranted further investigation.

A sequential comparison on the risk of haemorrhage with different sizes of biopsy needles for stereotactic brain biopsy.

AIM: To compare the risk of postoperative haemorrhage with different sizes of brain biopsy needles. PATIENTS AND METHOD: A cohort of patients using a 2.5-mm outer diameter side-cutting biopsy needle was compared to a subsequent cohort using a 1.8-mm needle of the same type. All data were collected prospectively. A CT scan was done within 12 h after surgery. Any visible haemorrhage at the operated site was documented. RESULTS: From 2007 to 2013, 54 stereotactic brain biopsies (all frameless except for one frame-based) were performed. The 2.5-mm group comprised 29 procedures from 2007 to 2009. The 1.8-mm group comprised the subsequent 25 procedures. The diagnostic yields were 90 and 96% in the 2.5- and the 1.8-mm group, respectively (p = 0.615). Comparing the 2.5- and the 1.8-mm group, haemorrhage was significantly reduced: incidence (72 vs. 40%, p = 0.016); size of haemorrhage (mean 7.2 vs. 2.6 mm, p = 0.002); proportion of haemorrhage size >10 mm (34.5 vs. 4%, p = 0.006). Symptomatic haemorrhage rates were 3.4 and 0.0% in the 2.5- and the 1.8-mm group, respectively (p = 1.00). CONCLUSION: The 1.8-mm outer diameter needle carried a lower risk of postoperative haemorrhage than the 2.5-mm one, without compromising the diagnostic yield.

Clinical study on cognitive dysfunction after spontaneous subarachnoid haemorrhage: patient profiles and relationship to cholinergic dysfunction.

PURPOSE: We aimed to explore the cognitive profiles of subarachnoid haemorrhage patients who returned to the community, along with the associated risk factors. METHODS: We recruited 40 Chinese patients with spontaneous subarachnoid haemorrhage 7-27 months after the initial presentation. They had all been discharged to their homes or to care homes for the elderly. For cognitive assessment, we employed the Cognitive Subscale of the Alzheimer Disease Assessment Scale (ADAS-cog) for global cognitive function, the Frontal Assessment Battery (FAB) for frontal lobe function, and the Rivermead Behavioural Memory Test (RBMT) for everyday memory function. RESULTS: An ADAS-cog of more than 21/85 (poor global cognitive function) was noted in 14 (35%) patients. A FAB of less than 12/18 (poor frontal lobe function) was noted in 13 (27.5%) patients. An RBMT score of less than 15/26 (poor everyday memory function) was noted in 17 (43.6%) patients. Poor cognitive function was found to be associated with chronic hydrocephalus (in terms of FAB), with clinical vasospasm (in terms of RBMT), and with cerebral infarction (in terms of RBMT). CONCLUSIONS: Poor cognitive function was common and occurred in up to 43.6% of the patients, with the verbal and behavioural memory aspects predominantly affected. We did not find a significant association between cholinergic dysfunction and cognitive dysfunction. Organization of future drug trials and cognitive rehabilitation should take into account the association between frontal lobe dysfunction and chronic hydrocephalus.

Successful treatment of multiple subdural empyemata caused by Mycoplasma hominis in a newborn.

We report a case of neonatal subdural empyema caused by Mycoplasma hominis. The infant sustained severe birth-related eye injury and subsequently developed multiple subdural empyemata. This report illustrates the clinical presentation of this unusual infection and the crucial role of neurosurgical intervention and specific antimicrobial therapy for its successful management.