Long-Term Dosing of Intrathecal Baclofen in the Treatment of Spasticity After Acquired Brain Injury

On the recovery of disorders of consciousness under intrathecal baclofen administration for severe spasticity-An observational study

BACKGROUND

Occasionally, patients show dramatic recovery from disorders of consciousness (DOC) under intrathecal baclofen (ITB), an established treatment option for severe supraspinal spasticity. Anecdotal explanations for ITB-related recovery of cognition include modulation of afferent impulses at the spinal level, thereby reducing spasticity-related proprioceptive information overload within cortico-thalamo-cortical connections.

OBJECTIVE

In this retrospective patient chart analysis, we assessed whether a reduction in spasticity would be associated with an increase in Coma Recovery Scale revised (CRS-R) scores in a larger sample of patients than previously published.

METHODS

From a hospital-based ITB treatment register, we extracted data from 26 patients with DOC and severe supraspinal spasticity who improved by >2 points on the Coma Recovery Scale revised (CRS-R) within 6 months after ITB treatment initiation. We assessed Modified Ashworth scale (MAS) scores and CRS-R scores on admission (PRE) and 3 and 6 months after initiation of ITB treatment (3M, 6M). We performed correlation analysis of the scores and their respective changes (PRE to 3M, 3M to 6M). We also correlated the time from acute event until ITB initiation to CRS-R scores at 3M and 6M.

RESULTS

ITB led to significant improvement in spasticity based on MAS scores, which did not correlate to the improvements seen in CRS-R total and subscale scores. Daily ITB dose did neither correlate to MAS scores nor to CRS-total scores in the whole patient group, but after 3 months, ITB dose correlated to some CRS-R subscale scores in some patient subgroups. Time until ITB treatment did not correlate to CRS-R scores later on.

CONCLUSIONS

Our data confirm that ITB may exert beneficial effects in selected DOC patients with respect to improved cognitive functions, which, however, do not correlate to its antispastic effect. The lack of correlation between time to ITB and CRS-R outcome, but significant CRS-R improvements following pump implantation, renders spontaneous remissions unlikely and leaves room for alternative pharmacological mechanisms.

Ivermectin Increases Random-Pattern Skin Flap Survival in Rats: The Novel Role of GABAergic System

BACKGROUND

Ivermectin (IVM) was first used as an antiparasitic agent; however, the role of this drug evolved into a broad spectrum. Many mechanisms have been proposed, including interaction with the GABAergic system. Considering the presence of GABA receptor in the skin tissue and its role in ischemia-reperfusion I/R injury, we aimed to evaluate the effect of IVM through GABA receptors on random-pattern skin flap survival.

METHODS

Sixty Wistar male rats were used. Multiple doses of IVM (0.01, 0.05, 0.2, and 0.5 mg/kg) were injected intraperitoneally before the surgery. Baclofen (selective GABAB agonist) and bicuculline (selective GABAA antagonist) were administered in combination with IVM to assess the role of the GABAergic system. Histopathological evaluations, immunohistochemical staining, quantitative assessment of IL-1β and TNFα, and the expression of GABAA α1 subunit and GABAB R1 receptors were evaluated in the skin tissue.

RESULTS

IVM 0.05 mg/kg could significantly increase flap survival compared with the control group (P < 0.001). Subeffective dose of baclofen (0.1 mg/kg) had synergistic effect with the subeffective dose of IVM (0.01 mg/kg) (P < 0.001), whereas bicuculline 1 mg/kg reversed the effect of IVM (0.05 mg/kg) (P < 0.001). IVM 0.05 mg/kg could also decrease the IL-1β and TNFα levels and increase the expression of GABAA α1 subunit and GABAB R1 receptors in the flap tissue compared with the control group.

CONCLUSIONS

IVM could improve skin flap survival, probably mediated by the GABAergic pathway. Both GABAA and GABAB receptors are involved in this process. This finding may repurpose the use of old drug, "Ivermectin."

The Roles of GABA in Ischemia-Reperfusion Injury in the Central Nervous System and Peripheral Organs

Ischemia-reperfusion (I/R) injury is a common pathological process, which may lead to dysfunctions and failures of multiple organs. A flawless medical way of endogenous therapeutic target can illuminate accurate clinical applications. γ-Aminobutyric acid (GABA) has been known as a marker in I/R injury of the central nervous system (mainly in the brain) for a long time, and it may play a vital role in the occurrence of I/R injury. It has been observed that throughout cerebral I/R, levels, syntheses, releases, metabolisms, receptors, and transmissions of GABA undergo complex pathological variations. Scientists have investigated the GABAergic enhancers for attenuating cerebral I/R injury; however, discussions on existing problems and mechanisms of available drugs were seldom carried out so far. Therefore, this review would summarize the process of pathological variations in the GABA system under cerebral I/R injury and will cover corresponding probable issues and mechanisms in using GABA-related drugs to illuminate the concern about clinical illness for accurately preventing cerebral I/R injury. In addition, the study will summarize the increasing GABA signals that can prevent I/R injuries occurring in peripheral organs, and the roles of GABA were also discussed correspondingly.

The Palliative Use of Intrathecal Baclofen in Niemann-Pick Disease Type C

Niemann-Pick disease type C is a rare progressive genetic disorder that leads to the abnormal accumulation of lipids within various tissues of the body, including brain tissue and liver. There is a rapid progression of the disease, resulting in severe disability in only a few years after the first symptoms, and survival is not much longer. Spasticity, dystonia, and chronic pain are common findings that severely impact quality of life in these patients. Analgesic management with traditional pain medications is not always effective, and the risk for secondary effects in medically complex patients is high. Liver function is also a limiting factor in these patients. This is a case report of a boy with advanced Niemann-Pick disease type C with developmental regression, cataplexia, and seizures. His severe spasticity made positioning and care difficult, and intense pain required multiple hospitalizations. He had unsuccessfully trialed multiple drugs. An intrathecal baclofen pump was placed without surgical complications and resulted in positive clinical effects. Baclofen pumps have classically been used for spasticity management in adults and children with nonprogressive diseases such as cerebral palsy or spinal cord injury with relatively long life expectancies. In adults, they have been used in patients with multiple sclerosis; however, use in pediatric neurodegenerative diseases has scarcely been reported. The use of intrathecal baclofen in palliative settings might provide an additional resource to provide comfort and quality of life for children with neurodegenerative diseases not only at end-of-life stages but also earlier on.

Outcomes of intrathecal baclofen therapy in patients with cerebral palsy and acquired brain injury

Intrathecal baclofen (ITB) has been known to reduce spasticity which did not respond to oral medications and botulinum toxin treatment. However, few results have been reported comparing the effects of ITB therapy in patients with cerebral palsy (CP) and acquired brain injury. This study aimed to investigate beneficial and adverse effects of ITB bolus injection and pump therapy in patients with CP and to compare outcomes to patients with acquired brain injury such as traumatic brain injury and hypoxic brain injury. ITB test trials were performed in 37 patients (19 CP and 18 acquired brain injury). Based on ambulatory function, CP patients were divided into 2 groups: 11 patients with nonambulatory CP and 8 patients with ambulatory CP. Change of spasticity was evaluated using the Modified Ashworth Scale. Additional positive or negative effects were also evaluated after ITB bolus injection. In patients who received ITB pump implantation, outcomes of spasticity, subjective satisfaction and adverse events were evaluated until 12 months post-treatment. After ITB bolus injection, 32 patients (86.5%) (CP 84.2% versus acquired brain injury 88.9%) showed a positive response of reducing spasticity. However, 8 patients with CP had negative adverse effects. Particularly, 3 ambulatory CP patients showed standing impairment and 1 ambulatory CP patient showed impaired gait pattern such as foot drop because of excessive reduction of lower extremity muscle tone. Ambulatory CP patients received ITB pump implantation less than patients with acquired brain injury after ITB test trials (P = .003 by a chi-squared test). After the pump implantation, spasticity was significantly reduced within 1 month and the effect maintained for 12 months. Seventeen patients or their caregivers (73.9%) were very satisfied, whereas 5 patients (21.7%) suffered from adverse events showed no subjective satisfaction. In conclusion, ITB therapy was effective in reducing spasticity in patients with CP and acquired brain injury. Before ITB pump implantation, it seems necessary to perform the ITB bolus injection to verify beneficial effects and adverse effects especially in ambulatory CP.