Neuroanatomy of financial decisions

INTRODUCTION

Neuroeconomics is a new science that studies the brain processes involved in taking decisions, particularly related to economy and it has experienced an important advance in the recent years due to the development of the new neuroimaging techniques, basically functional magnetic resonance imaging. The aim of this paper it to carry out a review of the literature on the different neurological mechanisms involved in taking financial decisions, the concerned brain structures and the diseases that can affect them.

SOURCES

We made a non systematic review of the literature in primary (PubMed) and secondary (Tripdatabase and Cochrane Library) bibliographic databases. We also used bibliography given by the Asociación Española de Neuroeconomía.

DEVELOPMENT

Brain reward and loss aversion systems suppose a balance that makes us take one or another decision. Dopamine plays an important role on it and several brain structures have been involved in this balance such as the amygdale, the insula, the medial prefrontal cortex, the anterior and posterior cingulated cortex, the accumbens nucleus and the ventral tegmental area. The alteration of this balance may produce inappropriate financial behaviors what may occur in common diseases including depression, mania, alcoholism, gambling and several impulse control disorders.

CONCLUSIONS

Neurologists should define our role in this interdisciplinary field due to the privileged position of our specialty to study how the brain works and due to the potential growing of this science in the near future.

[Relationship between fibrinolytic system and neurological diseases]

INTRODUCTION

The fibrinolytic system, also named plasminogen system is formed by a group of molecules that transforms plasminogen in its active form plasmine, which is able to participate in a number of pathophysiological processes.

AIM

To carry out a review of the literature and an analysis of the relationship between fibrinolytic system and neurological diseases and its potential therapeutic implications.

DEVELOPMENT

The fibrinolytic system has been involved in many different pathologies. Although its role in neurological diseases has always been thought to be scarce, many relations have been recently established. This way, fibrinolytic system seems to be involved not only in cerebrovascular diseases but also in epilepsy, inflammatory diseases such as multiple sclerosis, alterations of the dopaminergic system, learning disorders and several lesions of the peripheral nervous system. Different genotypes of several components of this system have been related as risk or protector factors to the development of these neurological diseases and information to this respect is rapidly increasing.

CONCLUSIONS

A better knowledge about the relations between the fibrinolytic system and neurological diseases could clarify several aspects about their pathophysiology and it could suppose future prevention and treatment lines.

Acquired chronic hepatocerebral degeneration due to cirrhosis from non-alcoholic steatohepatitis

INTRODUCTION AND OBJECTIVE

Acquired chronic hepatocerebral degeneration, acquired hepatolenticular degeneration or pseudo-Wilson is an infrequent disorder with a hepatic origin. Cases in the literature are scarce and it is frequently confused with hepatic encephalopathy and Wilson s disease. The aim of this essay is to report a patient suffering from this disorder due to cirrhosis from non-alcoholic steatohepatitis.

CASE REPORT

We present a 54-year-old man diagnosed from cirrhosis grade B9 of the Child Pugh classification. He progressively developed a picture with bradylalia, mild postural and action tremor and spatial and temporal disorientation. Further studies demonstrated an increase of the values of hepatic transaminases and a hyperintensity in the basal nuclei in the cerebral magnetic resonance imaging. Clinical and radiological data established the diagnosis of hepatocerebral degeneration.

CONCLUSIONS

Acquired chronic hepatocerebral degeneration is a disorder rarely reported in the literature that it is usually confused with other diseases. We alert about the need of having this diagnosis into account with patients developing neurological symptoms after hepatic disease.

[Glatiramer acetate in interferon beta non respondent relapsing-remitting multiple sclerosis]

INTRODUCTION AND OBJECTIVE

There are 4 immunomodulator treatments approved as first line therapy for patients with re-lapsing-remitting multiple sclerosis (RRMS). The objective of this study is to assess if glatiramer acetate (GA) is useful or not in patients who have discontinued interferon beta due to a suboptimal response or adverse events.

METHODS

This is an observational and retrospective study in RRMS patients who discontinued IFN-beta therapy (2.9+/-2.4 years of treatment) and switched to GA (1.9+/-1.4 years). They were classified in 2 groups depending on the reason for discontinuation: suboptimal response or side effects. In both treatments we analysed number of relapses, treatment duration and causes of discontinuation.

RESULTS

We included 58 patients of which 20 discontinued IFN-beta for lack of effectiveness whereas 38 were due to adverse events. Patients who discontinued for suboptimal response changed from 1.38 +/- 0.95 relapses per year with IFN-beta to 0.52+/-0.86 with GA. Patients who discontinued for adverse events changed from 0.33 +/- 0.64 relapses per year with IFN-beta to 0.37+/-0.79 with GA.

CONCLUSIONS

GA can be considered a good alternative treatment for MS patients with a suboptimal response or adverse events with IFN-beta which confirms the existence of different mechanisms of action in both drugs.

[Worsening of migraine symptoms due to giant pineal cyst apoplexy]

INTRODUCTION

Although the association between headaches and pineal gland cysts has been suggested on a number of occasions, no precise evidence of exactly what this relation involves has been produced to date. It is known, however, that a cyst in the pineal gland can bring on or worsen headaches, especially if it is large or there has been bleeding, due to obstructive compromise in the third ventricle and the resulting hydrocephalus that is produced.

CASE REPORT

A 15 years-old male who had suffered from migraine from the age of 6 years and who suddenly experienced a worsening of his headaches, both as regards their frequency and their intensity, over the previous days; no known precipitating factor appeared to be involved. Magnetic resonance imaging of the brain revealed the presence of a giant cyst in the pineal gland, with a notable amount of blood inside it, which was producing an obstructive hydrocephalus. The decision was made to resort to surgical treatment, with resection of the cyst and placement of a shunt valve. As a result the patient's headaches improved greatly and this improvement continued throughout a six-month follow-up.

CONCLUSIONS

Worsening of a headache, in this case migraine, for no apparent cause must make us consider secondary processes, although they may be as rare as the one described here.

[Sexual intercourse as a trigger of transient global amnesia]

INTRODUCTION

Transient global amnesia (TGA) is characterised by impairment of anterograde memory and, to a certain extent, retrograde memory, which is associated with mild temporal and spatial disorientation that is completely re-established after a few hours. There are different hypotheses about its pathogenesis, including theories about a possible epileptic, migrainous or ischaemic foundation or its being due to venous congestion in the hippocampuses, although the cause remains unknown. In the same way, many precipitating factors have been related to this disorder, including pain, anxiety, changes in temperature, exercise, Valsalva manoeuvres, diagnostic testing, interventionism and long-distance flights. Sexual intercourse has also been related to this condition, although how it can exert an influence is not known and few cases have been reported in the literature to date.

CASE REPORTS

Six patients who suffered from signs and symptoms of TGA that were clearly related to a sexual relationship, in whom both the neurological examination and the complementary tests that were performed were completely normal. We also gather the evidence in favour and against the association between intercourse and this condition.

CONCLUSIONS

Although the pathophysiological mechanisms that link sexual intercourse with TGA are unknown, the relation between them appears increasingly more often in the literature. We draw attention to the need to take sexual activity into account as a possible precipitating factor in patients suffering from this disorder.

[Botulinum toxin type A in the treatment of neuropathic pain in a case of postherpetic neuralgia]

INTRODUCTION

Botulinum toxin type A has been used in a wide range of neurological diseases such as migraine, cervical dystonia, spasticity or tics. However, the use of this drug in the treatment of neuropathic pain is still uncommon despite the fact that more and more cases supporting its role as an alternative treatment are emerging in the literature.

CASE REPORT

Herein, we report a case of an 83 year old woman who suffered from severe pain with neuropathic characteristics due to postherpetic neuralgia which was refractory to different conventional therapies. The neuropathic pain was dramatically improved by multiple botulinum toxin type A injections and the analgesia lasted 2 months. Treatment was well tolerated and there were no side effects.

CONCLUSIONS

Using botulinum toxin has been effective and well tolerated in the treatment of postherpetic neuralgia in our patient. Despite the fact that its action mechanisms is still unknown, we consider that botulinum neurotoxin may be an alternative treatment in relieving refractory neuropathic pain and that controlled studies are needed to study this possibility.

[Unusual complications of the lumboperitoneal shunt as treatment of benign intracranial hypertension]

INTRODUCTION

Intracranial hypertension is a picture characterized by elevated cerebrospinal fluid pressure that may cause some different complications including optic disc edema and visual accuracy alterations. Although treatment is generally pharmacological, invasive therapeutical techniques such as optic nerve sheath fenestration and lumboperitoneal shunt are sometimes required. The latter one is a technique that usually provides good results with a low complication rate, including infections, mechanical failure and overdrainage.

CASE REPORT

We report the case of a 40 year-old female patient with an idiopathic intracranial hypertension picture who required a lumboperitoneal shunt due to her progressive deterioration. After a few hours, the patient developed an intracerebral hematoma and subarachnoid hemorrhage, and some days later she developed a venous sinus thrombosis. These two complications, although described in the literature, are very unusual.

CONCLUSIONS

Even though the lumboperitoneal shunt is a safe technique with good results, it is not exempt from complications. We alert about the need to take into account subarachnoid hemorrhage and venous sinus thrombosis as possible complications in the followup of these patients.

[Rotigotine in the treatment of Parkinson's disease. A study on a sample of 150 patients]

INTRODUCTION

Rotigotine is a non-ergot dopamine agonist that has become the first treatment for Parkinson's disease formulated as a transdermal release system. Its side effects are very similar to those of other dopamine agonists, as well as those deriving from the site of application, while its advantages include a once-daily administration, the absence of interactions with foods and steady levels in plasma.

AIM

To determine the frequency of and reasons for withdrawing rotigotine in 150 consecutive patients diagnosed with Parkinson's disease.

PATIENTS AND METHODS

A retrospective analysis was carried out using the database at our Movement Disorders Unit in order to identify the first 150 patients who were treated with rotigotine. Only patients with Parkinson's disease who were free of intracranial lesions, psychiatric pathologies or dementia were eligible for inclusion in the sample. Patients were evaluated before and at two, four and six months after beginning treatment with rotigotine.

RESULTS

In all, 85 males and 65 females were identified. A total of 110 of them had previously been treated with dopamine agonists. Although 12% of the patients dropped out, 88% of them continued the treatment. The reasons for withdrawing were worsening of the clinical condition (12 patients), lack of effectiveness (three patients), drowsiness (two patients) and dyskinesias (one patient).

CONCLUSIONS

Rotigotine is safe and effective as medication in the treatment of Parkinson's disease. The fact that most of the drop-outs were due to a worsening of the clinical signs and symptoms after changing from another dopamine agonist suggests the need for an equivalence between other agonists and rotigotine.

[Zonisamide in refractory essential tremor]

INTRODUCTION

Essential tremor is one of the most frequent movement disorders. It is characterized by postural and action tremor that may affect different regions of the body. Among current treatments propranolol and primidone are included. However, these two drugs have demonstrated a limited efficacy and several adverse events. Additionally, they are contraindicated in patients with cardiac insufficiency and several respiratory diseases. New antiepileptic drugs are revealing as a possibility in the treatment of this disease. AIM. To evaluate efficacy and tolerability of zonisamide in the treatment of essential tremor.

PATIENTS AND METHODS

We perform a retrospective study about 13 patients with essential tremor refractory to an average of 2.8 drugs. Age, sex, zonisamide dosage, adverse events, duration and response to the treatment before and after the treatment were collected and analysed. Average zonisamide dosage was 215 mg/day and average duration of the treatment was 121 days.

RESULTS

Nine of 13 patients included in our study experienced a good response. A positive response was understood as a decrease on the limitation of daily activities and an improvement on neurological examination. Zonisamide was well tolerated and no patient abandoned the study for this reason.

CONCLUSIONS

Our data suggest that zonisamide is effective and well tolerated in the treatment of essential tremor. Placebo-controlled and bigger studies are warranted to confirm these results.

[Relationship between essential tremor, Parkinson's disease and dementia with Lewy bodies]

INTRODUCTION

Although essential tremor (ET), Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are considered to be distinct illnesses, there is a certain overlap between some of their clinical, pathological and genetic features.

AIM

To conduct a critical examination of the evidence for and against the association between these three pathological conditions.

DEVELOPMENT

The body of evidence supporting the notion of a relation between ET and PD is growing all the time; the same can be said of the fact that a postural tremor may appear years before the onset of other extrapyramidal symptoms, the involvement of common genes in the development of both conditions or the presence of common pathological findings. In addition, it has also been suggested that there are several aspects linking PD and DLB, and it has even been claimed that that they might be part of the clinical spectrum of the same disease. The concept of ET as a benign single-symptom disease has changed in recent years and, since it has been related to cognitive disorders and Lewy bodies in the central nervous system, it is now considered to be a neurodegenerative pathology. CONCLUSIONS. ET, PD and DLB could represent different points on the same clinical spectrum.

[Soya supplements in the treatment of neuropathic pain]

INTRODUCTION

Neuropathic pain is a typical symptom of a number of neurological diseases that is often difficult to treat. Drugs used include antidepressants, opiates, topical agents and antiepileptic drugs and, despite the fact that combination therapy regimens are becoming increasingly frequent, a considerable percentage of cases are pharmacoresistant. In this regard, other therapeutic approaches, such as diet, can play a fundamental role. In spite of the use of soya as treatment for certain situations, such as premenstrual or joint pain, and the fact that it has been shown to be effective in preventing the development of neuropathic pain in animal pain models, no studies have been conducted to examine its role as a possible analgesic in neuropathic pain.

CASE REPORTS

Our study involved a series of nine patients (four males and five females) who were diagnosed with neuropathic pain due to varying aetiologies which was refractory to an average of 2.3 drugs; these subjects were treated with soya extracts and phytoestrogens. The mean dose was 300 mg every 12 hours and the follow-up lasted 62 days. Data concerning the intensity of the pain (according to a visual analogical scale), the number of days with pain and the side effects were collected and analysed. No improvement was observed in any of the variables under study, although there were no side effects either.

CONCLUSIONS

Soya supplements did not display any analgesic properties to combat neuropathic pain in our study. Nevertheless, given previous findings in other types of pain, the data obtained in animal models and the absence of side effects, we believe it is necessary to carry out further studies in this line.

[Painful legs and moving toes syndrome]

Painful legs and moving toes syndrome is a rare medical picture characterized by involuntary movements of the toes or the whole foot and pain in lower limbs. However, this must be kept in mind due to its association with other diseases and its possibility of being the first symptom. Spinal cord and cauda equina diseases, neuropathies, radiculopathies, drugs and other systemic diseases are the main cause of this syndrome although many cases are still idiopathic. Its diagnosis is essentially clinical and its treatment is complex, including different combinations of drugs and invasive techniques, and generally with a bad response.