Dr Aly received his MD (in 1999 ) and Master of General surgery ( in 2003) both from Mansura University in Egypt. After finishing a Neurosurgery residency, he worked as assistant lectuerer of neurosurgery in Mansura University for a couple of years. In 2007 he passed the examinations of Membership of Royal College of surgeons of England (MRCS). Thereafter, he went to Osaka University in Japan to pursue his Ph D in Neuroscience. He also has a 2-year clinical Fellowship in Funactional and Epilepsy surgery. He had several pulications in Neurosurgery, Neuroimage, and Pain Journals.
Abstract: We would like to thank Lopez JA and colleagues for their interest in our article1. Lopez JA reported a small series of spinal cord stimulation (SCS) for thalamic pain; 6 out of 8 patients (75%) achieved satisfactory pain relief on long-term 2. Lopez JA restricted their indication to patients with localized pain distribution which could be entirely covered by stimulation paraethesia; and this may explain their relatively high success rate 2. Unfortunately this work had not been published yet when we submitted our report for publication.
Lopez JA et al reported that our trial period (2-7days) was short. Actually, within this time frame we were able to unequivocally evaluate the analgesic effect of SCS in all patients. Generally, there is no consensus on the length of SCS trial period, and periods of one day to several weeks have been reported 2, 3. There is no doubt that long trial periods give a better opportunity to evaluate the exact response to SCS, but unfortunately this comes on the price of increasing the risk of infection.
In our series, we used to remove the trial electrodes, and discharge patients after the trial period. At the time of counseling the patients in the outpatient clinic, those who decided to proceed were scheduled for the second trial and permanent SCS implantation 1. Lopez JA et al disagree with this approach as they think it may increase the rate of local complications and the second electrode may fail to provoke the same parethesia. The rationale for our approach is that during trial stimulation patients tend to respond in an affirmative manner, and therefore overestimate the analgesic efficacy4. We believe that repeating trials before permanent implant of SCS electrodes will minimize this phenomenon. However, there is no evidence that our method can improve outcome. We did not have any added complications from second trial but obviously, it increases the cost of treatment. Finally, it is interesting to find that our results of SCS for CPSP could be reproduced at other institutes. Hopefully these reports will encourage other centers to use SCS for CPSP particularly in face of safety of SCS trials and limited therapeutic options for CPSP.
Abstract: Patients with Parkinson's disease (PD) reportedly show deficits in sensory processing in addition to motor symptoms. However, little is known about the effects of bilateral deep brain stimulation of the subthalamic nucleus (STN-DBS) on temperature sensation as measured by quantitative sensory testing (QST). This study was designed to quantitatively evaluate the effects of STN-DBS on temperature sensation and pain in PD patients. We conducted a QST study comparing the effects of STN-DBS on cold sense thresholds (CSTs) and warm sense thresholds (WSTs) as well as on cold-induced and heat-induced pain thresholds (CPT and HPT) in 17 PD patients and 14 healthy control subjects. The CSTs and WSTs of patients were significantly smaller during the DBS-on mode when compared with the DBS-off mode (P<.001), whereas the CSTs and WSTs of patients in the DBS-off mode were significantly greater than those of healthy control subjects (P<.02). The CPTs and HPTs in PD patients were significantly larger on the more affected side than on the less affected side (P<.02). Because elevations in thermal sense and pain thresholds of QST are reportedly almost compatible with decreases in sensation, our findings confirm that temperature sensations may be disturbed in PD patients when compared with healthy persons and that STN-DBS can be used to improve temperature sensation in these patients. The mechanisms underlying our findings are not well understood, but improvement in temperature sensation appears to be a sign of modulation of disease-related brain network abnormalities. Quantitative evaluation on the effect of deep brain stimulation of the subthalamic nucleus on temperature sensation and pain suggested that it could improve impaired temperature sensation in patients with Parkinson's disease.
Abstract: BACKGROUND:: Pain after traumatic brachial plexus avulsion (BPA) has two distinct patterns: continuous burning pain and paroxysmal shooting pain. Lesioning of the Dorsal Root Entry Zone (DREZotomy) is more effective for paroxysmal than continuous pain. It is unknown, however, whether electrical motor cortex stimulation (EMCS) has a differential effect on continuous versus paroxysmal BPA pain. OBJECTIVE:: To analyze the differential effect of EMCS and DREZotomy on continuous versus paroxysmal BPA pain in a series of fifteen patients. METHODS:: Fifteen patients with intractable BPA pain underwent DREZotomy alone (n = 7), EMCS alone (n = 4), or both procedures (n = 4). Pain intensity was evaluated using visual analog scale, and separate ratings were recorded for paroxysmal and continuous pain. Pain relief was categorized as excellent (>75% pain relief), good (50-75%), or poor (<50%). Favorable outcome was defined as good or better pain relief. RESULTS:: Eight patients had EMCS; seven were followed up for an average of 47 months. Of those seven patients, three (42%) with continuous pain had favorable outcomes compared to no patients with paroxysmal pain. Eleven patients had DREZotomy; ten were followed up for an average of 31 months. Of those ten patients, seven (70%) with paroxysmal pain had favorable outcomes compared to two (20%) with continuous pain. CONCLUSION:: EMCS was ineffective for paroxysmal pain, but moderately effective for continuous pain. DREZotomy was highly effective for paroxysmal pain but moderately effective for continuous pain. It may be prudent to use EMCS for residual continuous pain after DREZotomy.
Abstract: We read with great interest the manuscript of Bonilla et al. entitled “Pain and brachial plexus lesions: evaluation of initial outcomes after reconstructive microsurgery and validation of a new pain severity scale” [3]. The authors described a new pain scoring-scale to quantify pain after brachial plexus injuries and used it to assess patients' pain before and after reconstructive surgery. Within this scale, [3] the authors integrated pain intensity scale (measured on a scale ranging from 0 to 10), with other parameters like the disability in daily activities and sleep, pain frequency, use of pain medication, and the number of zones affected by pain.
We agree with the authors that the use of such a multidimensional pain scale would be useful as a standard outcome measure across studies for BPA pain. That would greatly enhance the comparability, validity and clinical applicability of these studies. Whereas most of available reports used pain intensity scales such as the visual analogue scale as the sole outcome measure, the new pain scale integrated factors beyond changes in pain intensity which may be more objective and of more relevance to the patient outcome.
One limitation of the above-mentioned pain scale is that it did not distinguish between the different patterns of BPA pain. It is well-known that BPA pain has two patterns which are quite distinct from each other in terms of frequency and pain quality [5, 6]. Continuous background pain is usually described as burning, throbbing, and/or aching sensations and continues for long duration, whereas paroxysmal pain is usually described as “electrical shock” or “shooting“ paroxysms and usually lasts only a few seconds [5, 6]. Although the authors included pain frequency [3], described as no pain to continuous pain, in their pain scale, this may not be sufficient to allow distinction between the two types of pain. Instead, we suggest that pain character (burning vs shooting), be also included during evaluation [1,4]. Each type of pain should be quantified separately using Visual analogue score [1,4]. Separate rating for the two patterns of pain will be particularly useful in evaluating the outcome of neurosurgical procedures for BPA pain [1,6]. Thereby, allowing clinicians to study the differential effects of the procedures on pain. Sindou et al reported that DREZ-otomy was more effective for paroxysmal than continuous pain [6]. They explained the differential effects of DREZ-otomy based on the distinct pain origin for each type of pain [6]. Paroxysmal pain is said to originate from hyperactive neurons in the dorsal horn, whereas continuous pain extend beyond the dorsal horn up to the thalamus [6]. Also recently, our group reported that electrical motor cortex stimulation was more effective for continuous than paroxysmal pain [1]. Therefore, it can be said that pain classification is important to appropriately select patients for treatment and to better understand the underlying mechanisms of pain as well [1,4]. Finally, such distinction goes in line with several previous reports which have emphathized that classifying neuropathic pain according to their different components will help to develop a mechanism-based treatment [2].
Abstract: BACKGROUND: Although spinal cord stimulation (SCS) has been shown to be effective
for treating neuropathic pain of peripheral origin, its effectiveness for central poststroke
pain (CPSP) is not well established.
OBJECTIVE:We report our experience with SCS in 30 consecutive patients with intractable
CPSP.
METHODS: All patients underwent a percutaneous SCS trial. When patients decided to
proceed, they received a permanent SCS system. Pain intensity was evaluated by a visual
analogue scale (VAS). The Patient Global Impression of Change (PGIC) scale was also
assessed at the latest follow-up visit as an indicator of overall improvement.
RESULTS: During trial stimulation, pain relief was good (≥50% VAS score reduction) in 9
patients (30%), fair (30%-49% reduction) in 6 patients (20%), and poor (<30% reduction)
in 15 patients (50%). Ten patients elected to receive a permanent SCS system. Nine of these
10 patients were followed long-term (mean, 28 months; range, 6-62 months). Seven patients
reported significant pain relief on the VAS (5 = good and 2 = fair). On the PGIC scale, 6 of
these 7 patients reported a rating of 2 (much improved) and 1 reported a rating of 3 (minimally
improved). Of the remaining 2 patients, 1 reported a rating of 4 (no change) and 1
reported a rating of 5 (minimally worse). The median VAS score in the 9 patients decreased
significantly from 8.6 (range, 6.0-10.0) to 4.5 (range, 3.0-8.0; P = .008). There were no significant
reported complications.
CONCLUSION: SCS may provide improved pain control in a group of patients with intractable
CPSP and may have therapeutic potential for intractable CPSP.
Abstract: Spinal cord stimulation (SCS) is an effective therapy for chronic neuropathic pain. However, the detailed mechanisms underlying its effects are not well understood. Positron emission tomography (PET) with H(2)(15)O was applied to clarify these mechanisms. Nine patients with intractable neuropathic pain in the lower limbs were included in the study. All patients underwent SCS therapy for intractable pain, which was due to failed back surgery syndrome in three patients, complex regional pain syndrome in two, cerebral hemorrhage in two, spinal infarction in one, and spinal cord injury in one. Regional cerebral blood flow (rCBF) was measured by H(2)(15)O PET before and after SCS. The images were analyzed with statistical parametric mapping software (SPM2). SCS reduced pain; visual analog scale values for pain decreased from 76.1+/-25.2 before SCS to 40.6+/-4.5 after SCS (mean+/-SE). Significant rCBF increases were identified after SCS in the thalamus contralateral to the painful limb and in the bilateral parietal association area. The anterior cingulate cortex (ACC) and prefrontal areas were also activated after SCS. These results suggest that SCS modulates supraspinal neuronal activities. The contralateral thalamus and parietal association area would regulate the pain threshold. The ACC and prefrontal areas would control the emotional aspects of intractable pain, resulting in the reduction of neuropathic pain after SCS.
