Diphenhydramine is effective in the treatment of idiopathic dystonia

Movement disorders in autoimmune encephalitis: an update

Autoimmune encephalitis (AE) is a form of encephalitis resulting from an immune response targeting central nervous system antigens, which is characterized by cognitive impairment, neuropsychiatric symptoms, seizures, movement disorders (MDs), and other encephalopathy symptoms. MDs frequently manifest throughout the progression of the disease, with recurrent involuntary movements leading to discomfort and, in some cases, necessitating admission to the intensive care unit. Prompt identification and management of MDs can aid in the diagnosis and prognosis of AE. This review synthesizes current knowledge on the characteristics, underlying mechanisms, and treatment options for MDs in the context of AE.

Efficacy of Combination Haloperidol, Lorazepam, and Diphenhydramine vs. Combination Haloperidol and Lorazepam in the Treatment of Acute Agitation: A Multicenter Retrospective Cohort Study

BACKGROUND

Antipsychotic and sedative combinations are commonly used for treating agitation in the emergency department despite limited evidence regarding their comparative safety and efficacy.

OBJECTIVES

To compare the efficacy and safety of combination haloperidol, lorazepam, and diphenhydramine (B52) to combination haloperidol and lorazepam (52) in treating acute agitation.

METHODS

This multicenter, retrospective cohort study included adult patients ≥ 18 years of age who received either B52 or 52 at a Banner Health facility between August 2017 and September 2020. Patients were excluded if they had a pre-existing movement disorder or were withdrawing from alcohol. The primary outcome was administration of additional agitation medication(s) within 2 h of B52 or 52. Secondary outcomes included incidence of extrapyramidal symptoms, length of stay, and additional safety measures.

RESULTS

There was no difference in administration frequency of additional agitation medication(s) (B52: n = 28 [14%] vs. 52: n = 40 [20%]; p = 0.11). Patients who received 52 were more likely to require an antimuscarinic medication within 2 days (15 vs. 6 patients, p = 0.04). Of the patients who received an antimuscarinic medication, none had documented extrapyramidal symptoms. The 52 group had shorter length of stay (13.8 vs. 17 h; p = 0.03), lower incidence of hypotension (7 vs. 32 patients; p < 0.001), and oxygen desaturation (0 vs. 6 patients; p = 0.01), and fewer physical restraints (53 vs. 86 patients; p = 0.001) compared with the B52 group.

CONCLUSIONS

Both the B52 and 52 combinations infrequently required repeat agitation medication; however, the B52 combination resulted in more oxygen desaturation, hypotension, physical restraint use, and longer length of stay.

Treatment of Dystonia: Medications, Neurotoxins, Neuromodulation, and Rehabilitation

Dystonia is a complex disorder with numerous presentations occurring in isolation or in combination with other neurologic symptoms. Its treatment has been significantly improved with the advent of botulinum toxin and deep brain stimulation in recent years, though additional investigation is needed to further refine these interventions. Medications are of critical importance in forms of dopa-responsive dystonia but can be beneficial in other forms of dystonia as well. Many different rehabilitative paradigms have been studied with variable benefit. There is growing interest in noninvasive stimulation as a potential treatment, but with limited long-term benefit shown to date, and additional research is needed. This article reviews existing evidence for treatments from each of these categories. To date, there are many examples of incomplete response to available treatments, and improved therapies are needed.

Treatment of dystonia and tics

Treatment of dystonia and tics continues to evolve. In dystonia, while oral agents such as benzodiazepines, baclofen and anticholinergics remain in use, botulinum toxin (BoNT) continues to be regarded as the treatment of choice for focal and segmental dystonia, but new preparations are being studied. While deep brain stimulation (DBS) has typically focused on targeting the globus pallidus internus (GPi) when treating dystonia, more recent research has expanded the targets to include subthalamic nucleus (STN) and other targets. In addition to DBS, thalamotomies continue to show therapeutic benefit in focal hand dystonias. Treatment of tics includes a growing armamentarium of options besides the three FDA-approved drugs, all dopamine receptor blockers (haloperidol, pimozide and aripiprazole). Because of lower risk of adverse effects, dopamine depleters (e.g. tetrabebazine, deutetrabenazine, and valbenazine), along with novel D1 receptor antagonists, are currently studied as treatment alternatives in patients with tics. Practice guidelines for the treatment of tics and Tourette syndrome have been recently updated. Data regarding the use of DBS in treatment of tics remains relatively sparse, but international registries have expanded our understanding of the effect of stimulation at several targets.

Extrapyramidal signs occurring after sympathetic block for complex regional pain syndrome responding to diphenhydramine: Two case reports

RATIONALE

To present an unusual extrapyramidal motor response occurring after a sympathetic block in CRPS and its successful treatment with diphenhydramine.

PATIENT CONCERNS

Severe pain related to Complex Regional Pain Syndrome type 1 interfering with activities of daily living.

DIAGNOSES

Complex Regional Pain Syndrome type 1.

INTERVENTIONS

We report a video case reports of two patients with a diagnosis of CRPS type-I. Both patients exhibited similar presentation of unusual extrapyramidal motor response of the affected limb following lumbar sympathetic block. Both patients were treated with intravenous diphenhydramine to abort the extrapyramidal motor response.

OUTCOMES

Both patients similarly responded to treatment with intravenous diphenhydramine with abrupt resolution of the motor response.

LESSONS

Sympathetic blockade may interfere with the adaptive autonomic reflex circuits of the motor balance homeostasis in patients with complex regional pain syndrome. Disinhibition of extrapyramidal system may lead to immediate expression of extrapyramidal signs following the sympathetic block. Diphenhydramine, with its anti-histaminic and anticholinergic properties, may be effective in aborting such extrapyramidal signs, and should be considered as a treatment option in similar cases.

Diphenhydramine for Acute Extrapyramidal Symptoms After Propofol Administration

Extrapyramidal symptoms are an uncommon but well-recognized side effect after the administration of general anesthesia in patients without a significant neurologic history. Several case reports implicate propofol as the likely causative agent producing these symptoms, which include ballismus, dystonia, choreoathetosis, and opisthotonus. Currently, there is no clear consensus on first-line treatment of these symptoms. In each of the published cases, anticholinergic medications and benzodiazepines were central to initial management, although the speed and extent of symptom resolution were variable. Here we present a case of a 17-year-old boy with ulcerative colitis who presented with ballismus, torticollis, tongue thrusting, and oculogyric movements after colonoscopy under general anesthesia with propofol. The patient responded promptly to treatment with diphenhydramine. This is the first reported case in which diphenhydramine was successfully used as the primary treatment of severe extrapyramidal symptoms in a pediatric patient after propofol administration.

Current and future medical treatment in primary dystonia

Dystonia is a hyperkinetic movement disorder, characterized by involuntary and sustained contractions of opposing muscles causing twisting movements and abnormal postures. It is often a disabling disorder that has a significant impact on physical and psychosocial wellbeing. The medical therapeutic armamentarium used in practice is quite extensive, but for many of these interventions formal proof of efficacy is lacking. Exceptions are the use of botulinum toxin in patients with cervical dystonia, some forms of cranial dystonia (in particular, blepharospasm) and writer's cramp; deep brain stimulation of the pallidum in generalized and segmental dystonia; and high-dose trihexyphenidyl in young patients with segmental and generalized dystonia. In order to move this field forward, we not only need better trials that examine the effect of current treatment interventions, but also a further understanding of the pathophysiology of dystonia as a first step to design and test new therapies that are targeted at the underlying biologic and neurophysiologic mechanisms.

Naloxone-responsive acute dystonia and parkinsonism following general anaesthesia

Various movement disorders such as dystonia may acutely develop during or at emergence from general anaesthesia in patients with or without pre-existing Parkinson disease. These movements are triggered by a variety of drugs including propofol, sevoflurane, anti-emetics, antipsychotics and opioids. The postulated mechanism involves an imbalance between dopaminergic and cholinergic neurotransmitters in the basal ganglia. We report an acute, severe and generalised dystonic reaction in an otherwise healthy woman at emergence from general anaesthesia, dramatically reversed by the administration of naloxone, pointing to a potential role of the fentanyl and morphine that the patient had received. Recent literature on the mechanisms of abnormal movements induced by opioids are discussed. The severity of the reaction with usual doses of opioids, in a patient with no prior history of parkinsonism, led to further investigation that demonstrated the possibility of an enhanced susceptibility to opioids, involving a genetically determined abnormal function of glycoproteine-P and catechol-O-methyltransferase.

Enhancement of iontophoretic transport of diphenhydramine hydrochloride thermosensitive gel by optimization of pH, polymer concentration, electrode design, and pulse rate

The purpose of the present study was to explore the passive and electrically assisted transdermal transport of diphenhydramine hydrochloride (DPH) by iontophoresis. For better bioavailability, better patient compliance, and enhanced delivery of DPH, an iontophoretic drug delivery system of a thermosensitive DPH gel was formulated using Lutrol F-127. The study was conducted using silver-silver chloride electrodes across hairless pig skin. The effects of pH, polymer concentration, electrode design, and pulse rate on the DPH permeation were investigated. The relationship between temperature, viscosity, and conductance of DPH was correlated using conductometry. Iontophoretic transport of DPH was found to increase with a decrease in the pH of the medium and an increase in the surface area of the electrode. Viscosity measurements and flux calculations indicated the suitability of the Lutrol gel for transdermal iontophoretic delivery of DPH. Anodal pulsed iontophoresis with disc electrode significantly increased the DPH skin permeation as compared with the passive controls.

Non-cardiac adverse effects of antihistamines (H1-receptor antagonists)

Antihistamines, available without prescription in many countries, are generally considered to be safe medications; however, the old first-generation H1 antagonists commonly cause adverse central nervous system (CNS) effects, even when administered in usual doses. Patients may not be aware of these effects and do not necessarily develop tolerance to them. In contrast, the new, second-generation H1 antagonists are relatively free from adverse effects in the CNS, primarily because they do not cross the blood-brain barrier and block the important neurotransmitter function of histamine. Most of the H1 antagonists in current use are unlikely to cause cardiac toxicity. There is no evidence that H1 antagonists, which have been approved by regulatory agencies, have carcinogenic, tumour-promoting, or teratogenic effects in humans.

Dystonia: a case report and review

Dystonia is a movement disorder characterized by increased muscular tone for which surgical treatment has met with less than ideal results. Surgical treatment in patients with dystonia is often avoided due to the relative success of medical therapy. However, if expectations stay realistic and if the patient with dystonia is continuously evaluated, appropriate surgical measures may be taken when necessary to optimize patient satisfaction. The authors present a case of successful surgical treatment in a patient with a relatively static but crippling lower extremity deformity. A review of dystonia is included with successful surgical treatment of this compound neurologic disease causing lower extremity deformity in a young female. Diagnosis and treatment options including surgical planning and principles in the dystonic patient are highlighted.

Ranitidine-induced acute dystonia

Acute dystonia is a dramatic form of extrapyramidal side effects of antipsychotic medications. Although extrapyramidal reactions have been noted in related drugs, there are no existing reports associated with ranitidine. This report describes a case of an acute dystonic reaction secondary to a commonly prescribed, currently approved over-the-counter drug, ranitidine.

An aggressive approach to limb dystonia: a case report

A 15-year-old boy presented with a severe fluctuating foot and ankle dystonia resulting from a basal ganglia insult at the age of 4. This followed an embolic event related to an undiagnosed prolapsed mitral valve. Functionally, the patient was ambulatory with rocker bottom crutches and an ankle-foot orthosis, but there were periods of up to a year when pain and increased dystonic deformity required him to use a wheelchair. A new orthotic was made nearly every month because the orthotist could find no material that would withstand his tone without breaking, yet he could not ambulate without one. Multiple interventions, including biofeedback, contrast baths, stretching and strengthening, oral lioresal (Baclofen), diazepam (Valium), benztropine mesylate (Cogentin), carbidopa-levodopa (Sinemet), carbamazepine (Tegretol), and injections of botulism toxin (BOTOX) were tried, all with minimal effects. Amputation was recommended, based on anatomic and functional considerations. The patient and his family adjusted well to this decision, although not all orthopedists and therapists adjusted easily to the choice. The patient is now functionally independent with a prosthesis and has a normal teenage lifestyle for the first time.