Treatment for Parkinson’s examined

It involved a study of the most efficacious surgical operations undertaken and pharmaceutical drugs used to treat these disorders as well genetic studies carried out to date.

The field of movement disorders is one of the most complex branches of neurology. The volume of knowledge acquired is so large that it has needed a number of neurologists to sub-specialise in the matter and multidisciplinary units have been created to tackle problems such as the diagnosis of Parkinson’s Disease and of atypical Parkinsonisms, the choice of the most suitable surgical therapies and pharmaceutical drugs or the carrying out of genetic studies.

Thus is 1998 the Movement Disorders Unit at Cruces Hospital in Bilbao was created with neurologists, neurosurgeons, neurophysiologists, anaesthetists, neuropsychologists and radiologists. Since its creation, more than 100 surgical operations have been carried out, the majority on patients with Parkinson’s Disease. Currently it is a centre of reference for functional surgery in the Autonomous Community of the Basque Country (CAPV), and even receives patients from other autonomous communities.

The PhD the neurologist Juan Carlos Gómez-Esteban presented at the University of the Basque Country (UPV/EHU), Results of clinical research at a movement disorders unit, brings together a number of different lines of research undertaken at the Cruces Hospital Movement Disorders Unit between 1998 and 2007. Mr Gómez-Esteban graduated in Medicine and General Surgery and his PhD, having received excellent ratings cum laude, was led by Dr. Juan José Zarranz Imirizaldu and Dr. Elena Lezcano García, both from the Department of Neurosciences of the Faculty of Medicine and Odontology at the UPV/EHU.

Results of the operations

The initial part of the thesis presented by Dr. Gómez-Esteban reviews the operations carried out at the Movement Disorders Unit; in concrete, analysing deep brain stimulation, a surgical procedure that acts on the nuclei deep inside the brain that do not function correctly in patients affected by different movement disorders. From his research he deduced that what is involved is an effective therapy for patients with advanced Parkinson’s and that the subthalamic nucleus (a small nucleus located at the base of the brain) is the surgical target that provides a more complete answer to an improvement in the symptoms of the illness. The operation involves implanting microelectrodes in this nucleus and which are controlled by a battery similar to a pacemaker.

Dr Gómez-Esteban states that the benefit of this type of operation for the symptoms affecting movement is similar to that obtained with dopaminergic pharmaceutical drugs (those containing dopamina precursors or behave similarly to them), with the exception of trembling, which responds better to surgical treatment rather than to pharmaceutical medicines. Another of the benefits of deep cerebral stimulation is the enhancement of the quality of life not only for the patient, but also for the carer.

It also produces improvements in verbal memory, but changes in verbal fluency or executive functions have not been detected. Although initially symptoms of depression may be produced as a reaction related to patient expectation and to the surgical process itself, Dr. Gómez-Esteban affirms that, in the medium and long term, there is an improvement in the symptoms of depression.

This research also showed that patients suffering from the illness known as Parkinson-type multiple system atrophy as well as those with a specific mutation of the LRRK2-Dardarina gene, do not respond to surgery as well as those suffering from Parkinson’s of unknown cause or from other, hereditary Parkinson’s.

Genetic research: new mutations

Hereditary forms of Parkinson’s and dementia with Lewy bodies (a recently discovered illness previously confused with Parkinson’s or Alzheimer) are not frequent. In fact, Dr. Gómez-Esteban states that genetic defects associated with this last illness have not been found to date. However, the Movement Disorders Unit has discovered a new mutation in Parkinson’s Disease (a specific mutation in the gene known as alpha-synuclein), which is also associated with Lewy Body Dementia. Also notable is the fact that patients registering such a mutation do not have a primary sleep disorder, a reduction in the REM phases (in which dreams are produced) and NREM (in which dreams are not produced), which could even precede motor symptoms.

Sleep fragmentation, psychotic symptoms and analysis of pharmaceutical drugs

Another problem for Parkinson’s sufferers is the fragmentation of sleep or the impossibility of continuous sleep and nicturia (orinating frequently during the night). According to Dr. Gómez-Esteban, the drugs acting directly on the Dopamine receptors appear to improve nicturia, although not improving night time sleep nor the presence of daytime hypersomnia (difficulty in staying awake). 21.9% of patients studied at the Movement Disorders Unit suffer, moreover, from restless legs syndrome, which gives rise to a worsening in the quality of night time sleep and the quality of life.

Dr. Gómez-Esteban also reviewed research of Parkinson’s Disease patients who had psychotic symptom, such as visual hallucinations. The clinical trials undertaken at the Cruces Hospital point to the pharmaceutical drug Ziprasidona as being efficacious as an antipsychotic, having few adverse effects on the motor system that coordinate movement and regulates muscular tone.