10Th International Symposium on Navigated Brain Stimulation In Neurosurgery & Neuromodulation
October 12 — October 13
10Th International Symposium on Navigated Brain Stimulation In Neurosurgery & Neuromodulation
October 12 — October 13
Deafness–dystonia–optic neuronopathy (DDON) syndrome, also known as Mohr-Tranebjærg syndrome, is characterized by hearing loss that begins early in life, problems with movement, impaired vision, and behaviorproblems. This condition occurs almost exclusively in males.
Coenen et al. from the Department of Stereotactic and Functional Neurosurgery, Department of Neurology and Neurophysiology, Department of Neuroradiology, University Hospital Freiburg and Parkinson-Klinik Wolfach, Germany, reported a 28-year-old man presented with a history of sensorineural deafness since early childhood treated with bilateral cochlear implants (CIs). He showed signs of debilitating dystonia that had been present since puberty. Dystonic symptoms, especially a protrusion of the tongue and bilateral hand tremor, had not responded to botulinum toxin therapy. They diagnosed Mohr-Tranebjaerg syndrome (MTS).
Deep brain stimulation (DBS) of the bilateral globus pallidus internus was performed predominantly with stereotaxic computed tomography angiography guidance under general anesthesia. Electrophysiology was used to identify the target regions and to guide DBS electrode placement.
In the immediate postoperative course and stimulation, the patient showed marked improvement of facial, extremity, and cervical dystonia. More than 2 years after implantation, his dystonic symptoms had dramatically improved by 82%.
The use of DBS for the dystonia in MTS was previously described but not in the presence of bilateral CIs.
DBS in MTS may be a viable option to treat debilitating dystonic symptoms. They describe successful DBS surgery, despite the presence of bilateral CIs, and stimulation therapy over 2 years 1).
Eggink et al. from the Department of Neurology, Department of Genetics, Department of Rehabilitation, Department of Neurosurgery, University Medical Center Groningen, The Netherlands, reported two patients with dystonia-deafness syndrome due to a beta-actin gene mutation.
They report on disease course, genetic testing, and management of 2 patients, mother and daughter, presenting with dystonia-deafness syndrome.
After exclusion of known dystonia-deafness syndrome causes, whole-exome sequencing revealed a beta-actin gene mutation (p.Arg183Trp) in both patients. Although beta-actin gene mutations are generally associated with developmental Baraitser-Winter syndrome, dystonia-deafness syndrome has been reported once in identical twin brothers. Bilateral GPi-DBS led to a significant decrease of dystonia and regain of independency in our patients.
The p.Arg183Trp mutation in the beta-actin gene is associated with the clinical presentation of dystonia-deafness syndrome, even with only minimal or no developmental abnormalities of Baraitser-Winter syndrome. GPi-DBS should be considered to ameliorate the invalidating dystonia in these patients. 2).
Cif et al. reported in 2013 the article Progressive dystonia in Mohr-Tranebjaerg syndrome with cochlear implant and deep brain stimulation 3).
Patients with tremor predominant Parkinson’s disease (PD) achieve more improvement in tremor control after combined unilateral posteroventral pallidotomy and ventral intermediate nucleus thalamotomy 1). 2).
Twelve patients received unilateral PVP contralateral to the most affected side. The other 12 patients received simultaneous unilateral PVP and VIM thalamotomy contralateral to the most affected side. Assessment of results in both groups was achieved using both UPDRS “off” motor scores and UPDRS rest tremor subscores.
The mean UPDRS off motor score improved in the pallidotomy group from 61.3 preoperatively to 36.8 at 12 months. In the combined group, it improved from 59.6 to 35.2 at 12 months, with no statistically significant difference between both groups. On the other hand, while the mean tremor subscore in the pallidotomy group improved from a mean of 2.3-0.8, the tremors were abolished in all of the patients in the combined group except for 1 patient who showed slight infrequent tremors at 12 months 3).
Iacono et al. from the Division of Neurosurgery, Loma Linda University Medical Center, combined Vim/VOp junction thalamotomy and PVP in 29 patients with severe tremor, rigidity, and bradykinesia. Patients underwent unilateral Vim thalamotomy followed at the same sitting by PVP. The distinct physiological consequences of each procedure were documented by intraoperative electromyography (EMG) and video recording, revealing the effects on both tremor and agonist/antagonist co-contraction. Lack of reciprocal inhibition of antagonistic muscle groups often remained following thalamotomy but was eliminated by subsequent PVP. The complementary therapeutic effects of PVP and Vim thalamotomy may be due to the interruption of different neuronal circuits by the two procedures. The effect of Vim thalamotomy has been attributed to the interruption of the rubrothalamocortical loop. PVP interrupts the outflow of the globus pallidus internus (GPi), which may cause disinhibition of locomotor centers in the mesencephalon and spinal cord. There is no direct interruption of the rubrothalamocortical loop by PVP, explaining why this procedure sometimes exacerbates tremor in certain patients 4).
Christopher R. Honey et al., from the University of British Columbia, Vancouver, Canadadescribed a condition, hemilaryngopharyngeal spasm (HELPS), which can cause severe episodic stridor leading to unconsciousness in association with cough. The first recognized and surgically cured patient with HELPS was reported in 2017 1).
Three additional patients have been followed up for at least a year postoperatively.
Each patient presented with a similar pattern of episodic coughing and choking that increased in frequency, severity, and duration over years. The episodes eventually occurred while sleeping and could cause severe stridor with loss of consciousness. All three patients were initially misdiagnosed with a psychiatric illness and subjected to multiple intubations and one tracheostomy. Unilateral botulinum toxin injections in the vocal fold eased the severity of the throat contractions but not the cough. Magnetic resonance imaging showed a looping posterior inferior cerebellar artery juxtaposed to a vagus nerve in each case. Microvascular decompression (MVD) of that vessel relieved all symptoms. The introduction of this new medical condition may help a small cohort of patients with inducible laryngeal obstructions that have not responded to the current standard treatments. Patients are asymptomatic between episodes of progressively severe coughing and choking with stridor that may lead to intubation. Severe anxiety about the unpredictable symptoms is expected and may contribute to a psychiatric misdiagnosis. Microvascular decompression for HELPS is more difficult than that for trigeminal neuralgia because the involved nerve is more susceptible to manipulation. Ultimately, the final proof that HELPS is a real and distinct syndrome will require its recognition and successful treatment by colleagues around the world 2).
Tourette syndrome (also called Tourette’s syndrome, Tourette’s disorder, Gilles de la Tourette syndrome, GTS or, more commonly, simply Tourette’s or TS) is an inherited neuropsychiatric disorder with onset in childhood, characterized by multiple physical (motor) tics and at least one vocal (phonic) tic. These tics characteristically wax and wane, can be suppressed temporarily, and are preceded by a premonitory urge. Tourette’s is defined as part of a spectrum of tic disorders, which includes provisional, transient and persistent (chronic) tics.
Tourette’s was once considered a rare and bizarre syndrome, most often associated with the exclamation of obscene words or socially inappropriate and derogatory remarks (coprolalia), but this symptom is present in only a small minority of people with Tourette’s.
Tourette’s is no longer considered a rare condition, but it is not always correctly identified because most cases are mild and the severity of tics decreases for most children as they pass through adolescence. Between 0.4% and 3.8% of children ages 5 to 18 may have Tourette’s; the prevalence of other tic disorders in school-age children is higher, with the more common tics of eye blinking, coughing, throat clearing, sniffing, and facial movements. Extreme Tourette’s in adulthood is a rarity, and Tourette’s does not adversely affect intelligence or life expectancy.
Genetic and environmental factors play a role in the etiology of Tourette’s, but the exact causes are unknown. In most cases, medication is unnecessary. There is no effective treatment for every case of tics, but certain medications and therapies can help when their use is warranted. Education is an important part of any treatment plan, and explanation and reassurance alone are often sufficient treatment.
Comorbid conditions (co-occurring diagnoses other than Tourette’s) such as attention-deficit hyperactivity disorder (ADHD) and obsessive–compulsive disorder (OCD) are present in many patients seen in tertiary specialty clinics. These other conditions often cause more functional impairment to the individual than the tics that are the hallmark of Tourette’s; hence, it is important to correctly identify comorbid conditions and treat them.
The eponym was bestowed by Jean-Martin Charcot (1825–1893) on behalf of his resident, Georges Albert Édouard Brutus Gilles de la Tourette (1857–1904), a French physician and neurologist, who published an account of nine patients with Tourette’s in 1885.
Patients with Tourette syndrome diagnosed according to DSM-IV TR criteria with severe medication-recalcitrant disease referred to the Hazrat Rasool Hospital, Iran University of Medical Sciences, Tehran, Iran, were recruited for this study. They underwent bilateral anteromedial globus pallidus internus (amGPi) DBS with Medtronic Brain Neurostimulation Lead 3389. Patients were assessed using Yale Global Tic Severity Scale(YGTSS) and Gilles de la Tourette syndrome-quality of life scale (GTS-QOL) before and one year after DBS.
Six patients (four man and two women) with severe medication-recalcitrant TS, mean age of 26.33 ± 7.25 years fulfilled the follow up visits. All patients revealed significant improvement in tics severity one year after surgery. Based on YGTSS, total tic severity score decreased from 75.66 ± 16.54 to 28.33 ± 13.95, P-value:0.005. Quality of life improved significantly after DBS (26.66 ± 20.65 before and 70.00 ± 17.88 one year after surgery, P-value:0.02).
Results of this study in accordance to previous ones suggest AM-GPi DBS as an effective and well-tolerated therapeutic modality for patients with medication refractory TS 1).
Giorni et al. used intra-operative microelectrode recording during stereotactic neurosurgery to guide implantation of DBS lead.
Units in the medial anterior part of GPi of 7 Tourette’s syndrome patients under general anesthesia were firing at mean and median rate of 32.1 and 21 Hz respectively (n = 101), with 45% of spikes fired during bursts and 21.3 bursts per minute. In the latero-posterior part of GPi of 7 dystonic patients under local anesthesia the mean and median activity were 46.1 and 30.6 Hz respectively (n = 27), and a mean of 21.7 bursts per minute was observed, with 30% of all spikes occurring during these bursts.
Units activity pattern – slow-regular, fast-irregular or fast-regular were present in different proportions between the two targets.
The electrophysiological characteristics of the medial-anterior part of GPi and its latero-posterior portion can be used to assist DBS electrode targeting and also support the refinement of pathophysiological models of Tourette’s syndrome and Dystonia 2).
A study of 15 patients with long-term amGPi DBS for severe TS investigated whether a specific anatomical site within the amGPi correlated with optimal clinical outcome for the measures of tics, obsessive compulsive behaviour (OCB), and mood.
Validated clinical assessments were used to measure tics, OCB, quality of life, anxiety, and depression before DBS and at the latest follow-up (17-82 months). Electric field simulations were created for each patient using information on electrode location and individual stimulation parameters. A subsequent regression analysis correlated these patient-specific simulations to percentage changes in outcome measures in order to identify any significant voxels related to clinical improvement.
A region within the ventral limbic GPi, specifically on the medial medullary lamina in the pallidum at the level of the AC-PC, was significantly associated with improved tics but not mood or OCB outcome.
This study adds further support to the application of DBS in a tic-related network, though factors such as patient sample size and clinical heterogeneity remain as limitations and replication is required 3).
Richieri et al., report the first case of a patient with severe, intractable Tourette Syndrome (TS) with comorbid Obsessive Compulsive disorder(OCD), who recovered from both disorders with gamma knife stereotactic radiosurgery following deep brain stimulation (DBS). This case highlights the possible role of the internal capsule within the neural circuitries underlying both TS and OCD, and suggests that in cases of treatment-refractory TS and comorbid OCD, bilateral anterior capsulotomy using stereotactic radiosurgery may be a viable treatment option 4).
Complex gait test analysis systems are not generally available worldwide, and no simple system of assessing gait by observation has been validated specifically for use in patients with cerebral palsy.
Read et al., developed a visual gait analysis score for use in cerebral palsy. Videotaped sequences of patients were recorded before and after surgery as part of a three-dimensional gait study using a Vicon (Oxford, U.K.) gait analysis system. The score demonstrated good intraobserver and interobserver reliability. The numeric values of the score elements correlated well with the measurements obtained from instrumented gait analysis for the same patients, and the score was able to detect postoperative change 1).
EVGS can be a supportive tool that adds quantitative data instead of only qualitative assessment to a video only gait evaluation 2).
Robinson et al., propose an MCID value of 2.4 for the EVGS; representing the improvement in gait score after surgery that is likely to reflect a clinical improvement in function. This MCID is closely related to other studies defining post-operative improvements in kinematic data (GPS) and may offer guidance to post-surgical changes that might reasonably be expected to either improve or prevent deteriorating function 3).
36 children (age 4-13 y) with spastic diplegia (gross motor classification system level I (n=14), II (n=15) and III (n=7) were included retrospectively from the database of the VU University Medical Center Amsterdam. Children underwent Selective dorsal rhizotomy for spastic diplegia (SDR) between January 1999 and May 2011. Patients were included if they received clinical gait analysis before and five years post-SDR, age >4 years at time of SDR and if brain MRI-scan was available.
Overall gait quality was assessed with Edinburgh visual gait score (EVGS), before and five years after SDR. In addition, knee and ankle angles at initial contact and midstance were evaluated. To identify predictors for gait improvement, several factors were evaluated including: functional mobility level (GMFCS), presence of white matter abnormalities on brain-MRI, and selective motor control during gait (synergy analysis).
Overall gait quality improved after SDR, with a large variation between patients. Multiple linear regression analysis revealed that worse score on EVGS and better GMFCS were independently related to gait improvement. Gait improved more in children with GMFCS I & II compared to III. No differences were observed between children with or without white matter abnormalities on brain MRI. Selective motor control during gait was predictive for improvement of knee angle at initial contact and midstance, but not for EVGS.
Functional mobility level and baseline gait quality are both important factors to predict gait outcomes after SDR. If candidates are well selected, SDR can be a successful intervention to improve gait both in children with brain MRI abnormalities as well as other causes of spastic diplegia 4).
Anterior temporal lobectomy is often complicated by superior quadrantic visual field deficits (VFDs). In some cases this can be severe enough to prohibit driving, even if a patient is free of seizures. These deficits are caused by damage to Meyers loop of the optic radiation, which shows considerable heterogeneity in its anterior extent. This structure cannot be distinguished using clinical magnetic resonance imaging sequences.
van Lanen et al., developed a score method for the assessment of postoperative visual field defects after temporal lobe epilepsy surgery and assessed its feasibility for clinical use. A significant correlation between VFD and resection size for right-sided ATL was confirmed 3).
Cranial nerve (CN) deficits following anterior temporal lobectomy (ATL) are an uncommon but well-recognized complication. The usual CNs implicated in post-ATL complications include the oculomotor nerve, trochlear nerve, and facial nerves.
Injury to the – trigeminal nerve leading to neuropathic pain are described in 2 cases following temporal lobe resections for pharmacoresistant epilepsy. The possible pathophysiological mechanisms are discussed and the microsurgical anatomy of surgically relevant structures is reviewed.4).
To Kalyvas et al., knowledge, this is the third reported case in the literature. Unfortunately, the pathophysiological characteristics of muscle spasms in FA are not well explored and understood while the therapeutic mechanisms of the different treatments are rather vague. Taking into consideration the suggested spinal atrophy in FA, the clinical resemblance of FA and chronic spinal injury muscle spasms, together with the rapid ITB therapy effectiveness in alleviating FA muscle spasms, they attempted to suggest a putative pathophysiological mechanism acting at the spinal level and possibly explained by the presence of independent spinal locomotor systems producing muscle spasms. Specifically, overexcitement of these centers, due to loss of normal regulation from upper CNS levels, may result in the uncontrolled firing of secondary motor neurons and may be the key to producing muscle spasms. However, further research under experimental and clinical settings seems to be necessary 1).
A 50-year-old female patient with Friedreich ataxia (FA) was treated successfully with an intrathecal baclofen (ITB)-delivering pump for painful spasms. This is the second reported case of FA where ITB relieved painful and disabling spasms. Berntsson et al., suggest that ITB should be considered in the treatment of disabling spasms in patients with FA 2).
Ben Smail et al.,reported a patient suffering from Friedreich’s ataxia (FA) with very painful and disabling spasms that were improved markedly by intrathecal baclofen infusion. This is the first report of an intrathecal baclofen-delivering pump implantation in an FA patient 3).