Síndrome de Charles Bonnet / Charles Bonnet syndrome

En la medida que crece la población y aumenta el número de personas de la tercera edad con trastornos de la visión, se necesita cada vez más hacer conciencia del Síndrome de Charles Bonnet entre los oftalmólogos, psiquiatras y neurólogos. El propósito de la presente revisión es ofrecer una visión actualizada sobre sus aspectos clínicos, fisiopatológicos, epidemiológicos junto con las estrategias de manejo más razonables. Para ello se emprendió una búsqueda exhaustiva de la literatura más relevante, con el fin de comprender estos aspectos. El síndrome de Charles Bonnet es una entidad subreportada y subdiagnosticada que aparece en personas de la tercera edad, visualmente comprometidas. Estos pacientes por lo general tienen un estado cognoscitivo intacto aunque algunos autores sostienen que puede ser más frecuente en casos de deterioro cognoscitivo leve. Su fisiopatología aún es tema de debate pero las teorías mas aceptadas, hasta el momento, son la teoría de la denervación y el fenómeno de liberación. Los reportes de casos aislados señalan la posibilidad de intervenciones farmacológicas. Sin embargo, asegurar al paciente y tratar la patología visual son las piezas principales del tratamiento, no obstante, se necesitan más investigaciones que permitan aumentar las opciones terapéuticas eficaces.

As population grows, the number of older people with impaired vision does too.That is why ophthalmologists, psychiatrists and neurologists urgently require familiarization with the most important characteristics of Charles Bonnet syndrome. The purpose of this review is to give an update on its clinical aspects, pathophysiology, epidemiology and more reasonable management strategies of this syndrome. Accordingly, we carried out an exhaustive search of the relevant literature, in order to understand these issues. Charles Bonnet syndrome is a sub reported and sub diagnosed entity in visually impaired older people. These patients usually have an intact mental status although some authors claim that may be more common in cases of mild cognitive impairment. Its pathophysiology is still debated but most accepted theories are “the deafferentation theory” and “the phenomenon of liberation”. Isolated case reports point to the possibility of pharmacological interventions, however reassuring the patient and treating visual diseases are the main parts of treatment, more research is needed to allow the possibility of effective treatment options.

Alucinaciones visuales: síndrome de Charles Bonnet / Visual hallucinations: Charles Bonnet Syndrome

El síndrome de Charles Bonnet se caracteriza por alucinaciones visuales que se presentan en personas con una pérdida de visión severa y, generalmente, enpersonas de edad avanzada, con un estado mental normal. En este artículo se analizan las características de este síndrome, como la etiología, la fisiopatología y el diagnóstico diferencial, y se dan conocer criterios de diagnóstico para tener en cuenta en la práctica diaria, en especial para los optómetras, quedeben estar familiarizados con los signos y síntomas de este síndrome, ya que este grupo de pacientes casi siempre acude primero a la consulta optométrica. Aunque la condición se hizo pública en la comunidad médica hace más de doscientos años atrás, es muy poco diagnosticada por el desconocimiento existente sobre ella. En la práctica optométrica, se debe sospechar del síndrome de Charles Bonnet, especialmente en los grupos de pacientes que presentan alucinaciones visuales y debilidad visual o ceguera, evitando un diagnóstico psiquiátrico equivocado.

The Charles Bonnet Syndrome is characterized by visual hallucinations that occur in people with severe sight loss and usually in elderly people with a normal mental state. This article discusses the characteristics of this syndrome as the etiology, pathophysiology and differential diagnosis, and is known diagnostic criteria for consideration in daily practice. Especially for optometrists be who sould be familiar with the signs and symptoms of this syndrome, as this group of patients almost always come first to consult optometrists. Even though the condition was published in the medical community for over 200 years ago, it has been rarely diagnosed due to the lack of knowledge about it. In optometric practice, it is suspected Charles Bonnet Syndrome especially in this age group with visual hallucinations and visual weakness or blindness, avoiding a psychiatric diagnosis wrong.

Odontalgia atípica: revisão de literatura / Atypical odontalgia: review of literature

A Odontalgia Atípica (OA) é uma entidade clínica importante, pois a dor é neuropática por desaferentação e ocorre “no dente”, porém não é “dor de dente”. É caracterizada por dor em um dente ou dor em um sítio onde um dente foi extraído, com ausência de sinais clínicos ou radiográficos que acusem uma doença. Muitas vezes por insistência dos pacientes o tratamento endodôntico é realizado, mas não ocorre alívio da dor. Assim, tratamentos invasivos continuam sendo realizados incluindo retratamento endodôntico, apicetomia e finalmente a extração do dente. Sendo uma enfermidade que pode trazer alguma dificuldade diagnóstica para o cirurgião-dentista, o conhecimento de suas características se torna necessário. Deste modo, este artigo apresenta uma revisão de literatura sobre esta entidade, onde são abordados os seguintes tópicos: epidemiologia e sinais clínicos, critérios de diagnóstico, etiologia, diagnóstico diferencial e abordagens terapêuticas.

The Atypical Odontalgia (AO) it is an important clinical entity, because the pain is neuropatic for deafferentation and it happens “in the tooth”, however it is not “toothache.” It is characterized by pain in a tooth or pain in a ranch where a tooth was extracted, with absence of clinical signs or radiographics that accuse a disease. A lot of times for the patients’ insistence the endodontic treatment is accomplished, but it doesn’t happen relief of the pain. Like this, invasives treatments continue being accomplished including endodontic retreatment, apicectomy and finally the extraction of the tooth. Being an illness that can bring some diagnostic difficulty for the surgeon-dentist, the knowledge of their characteristics becomes necessary. This way, this article presents a literature revision on this entity, where the following topics are approached: epidemiology and clinical signs, diagnosis criteria, aetiology, differential diagnosis and therapeutic approaches.

Neurotransmitter receptor regulation after deafferentation in the visual system

The present study aimed at understanding the regulation of AMPA-type glutamate receptors (GluRs) and nicotinic acetylcholine receptors (nAChRs) during experimentally-induced neurodegeneration in the chick visual system. Immunohistochemistry, in situ hybridization, and RNAse protection techniques were used to verify the expression of GluR and nAChR subunits at several periods after deafferentation, ranging from 1 to 30 days. The results indicate that GluR1 and 2 expression changes in a biphasic way after deafferentation, decreasing after the shortest survival periods (1-4 days) and increasing afterwards. These effects clearly involve regulation of gene expression, as verified by in situ hybridization and RNAse protection. The regulation of the α2, α4, α5, and β2 nAChR subunits after deafferentation, on the other hand, exhibited a pattern that was exactly the opposite, with an early increase followed by a consistent decrease of expression until 30 days postlesion. Furthermore, nAChR changes were not apparently due to gene expression regulation, but instead by up-regulation/ down-regulation at a protein level. These results suggest that neurotransmitter receptors undergo differential plastic changes after deafferentation in the nervous system and contribute data to their possible role in neurodegeneration and neuroprotection processes.

Thalamic Deep Brain Stimulation for Deafferentation Pain: Case Report

Deep Brain Stimulation(DBS) analgesia is known to be an effective method of otherwise intractable chronic pain. The authors report a case of thalamic DBS for the relief of recurred deafferentation pain after DREZotomy. The patient was a 53-year-old female who had presented with neuropathic pain on right shoulder and upper extremity, owing to previous brachial plexus injury. She underwent DREZotomy on C3-C5 level with resultant pain relief, but symptom recurred 3 months after surgery. The authors performed left VPL nucleus stimulation, and good relief of the pain was achieved. We reviewed the pertinent literature, and discussed pathophysiology, clinical result of the DBS on deafferentation pain.

Alcohol and Aging:Neurobiological Effects

The alcohol problems in geriatric population have been strikingly increasing. The age differences of alcohol effect on the brain have been reported by several animal studies. Furthermore, cognitive disorders including dementia have been accompanied in many alcoholic patients, and evidences of alcohol-related brain damage have been identified by the clinical or histopathological studies. Therefore, alcohol seemed to accelerate aging by changing various age-related neurochemical or physiological processes, and produce alcohol-related direct neurotoxicity to result in cognitive disorders including dementia. To understand a mechanism of alcohol-related brain damage, alcohol-related brain structural changes and alcohol-related changes in neurotransmitter systems were reviewed at first, and then update molecular biologic theories including free radical reactions, excitotoxicity, nitric oxide, white matter damage, neurotrophin, liver-brain interaction and cholinergic deafferentation were also introduced.

Pain Relief from Dorsal Root Entry Zone(DREZ) Lesions Made with CO2 Laser in Brachial Plexus Injury Patients

Treatment of pain related to various types of deafferentation remains a neurosurgical challenge. Medical therapy and conventional surgical techniques for pain relief have not been effective due to this problem. Six patients with intractable pain following a brachial plexus injury were treated with dorsal root entry zone(DREZ) lesions. These lesions were made with CO2 laser. All patients were followed from 5 months to 5 years after surgery. Two-third of the patients were relieved of more than 50% of their preoperative pain. Post-operative neurosurgical complications were ipsilateral leg weakness and loss of proprioception in 2 cases. The laser technique is exact, makes uniform lesion, shortens the duration of the procedure, lessens cord manipulation and makes shalow penetration into the surrounding spinal cord. Dorsal root entry zone(DREZ) lesions made with CO2 laser appeared to be a satisfactory treatment for brachial plexus injury patients who have failed to respond to more conservative modes of therapy.

Dorsal Root Entry Zone Lesions for Intractable Pain Control

It is well documented that dorsal root entry zone(DREZ) lesions were good method to control intractable chronic deafferentation pain of spinal origin which was not controlled with various medical and surgical treatment. Experience with radiofrequency lesions of dorsal root entry zone in 3 of patients with post herpetic pain and 1 of patient with post amputation pain are reported. The follow-up period ranging from 3-20 months and all patients obtained satisfactory pain relief.