Medically unexplained neurological symptoms

Neurologic diagnostic criteria for functional neurologic disorders

The diagnosis of functional neurologic disorders can be challenging. In this chapter we review the diagnostic criteria and rating scales reported for functional/psychogenic sensorimotor disturbances, psychogenic nonepileptic seizures (PNES) and functional movement disorders (FMD). A recently published scale for sensorimotor signs has some limitations, but may help in the diagnosis, and four motor and two sensory signs have been reported as highly reliable. There is good evidence using eight specific signs for the differentiation of PNES from seizures. Recently, diagnostic criteria were developed for PNES; their sensitivity and specificity need to be evaluated. The definitive diagnosis of PNES can be made by recording typical positive features during the spells, and in a low proportion of cases, where the distinction with an organic etiology cannot easily be done, a normal electroencephalogram suggests the diagnosis. FMD diagnosis relies on diagnostic criteria, which have been refined over time and may be supplemented by laboratory tests in some phenotypes. Rating scales for PNES and FMD could be useful for severity measures, but several limitations remain to be addressed.

The value of 'positive' clinical signs for weakness, sensory and gait disorders in conversion disorder: a systematic and narrative review

Experts in the field of conversion disorder have suggested for the upcoming DSM-V edition to put less weight on the associated psychological factors and to emphasise the role of clinical findings. Indeed, a critical step in reaching a diagnosis of conversion disorder is careful bedside neurological examination, aimed at excluding organic signs and identifying 'positive' signs suggestive of a functional disorder. These positive signs are well known to all trained neurologists but their validity is still not established. The aim of this study is to provide current evidence regarding their sensitivity and specificity. We conducted a systematic search on motor, sensory and gait functional signs in Embase, Medline, PsycINfo from 1965 to June 2012. Studies in English, German or French reporting objective data on more than 10 participants in a controlled design were included in a systematic review. Other relevant signs are discussed in a narrative review. Eleven controlled studies (out of 147 eligible articles) describing 14 signs (7 motor, 5 sensory, 2 gait) reported low sensitivity of 8-100% but high specificity of 92-100%. Studies were evidence class III, only two had a blinded design and none reported on inter-rater reliability of the signs. Clinical signs for functional neurological symptoms are numerous but only 14 have been validated; overall they have low sensitivity but high specificity and their use should thus be recommended, especially with the introduction of the new DSM-V criteria.

Noninvasive radioelectric asymmetric brain stimulation in the treatment of stress-related pain and physical problems: psychometric evaluation in a randomized, single-blind placebo-controlled, naturalistic study

Background

The aim of this study was to investigate the effects of noninvasive radioelectric asymmetric conveyer brain stimulation (REAC-BS) on pain and physical problems, a measurement cluster of the Psychological Stress Measure (PSM) test. When the symptoms of pain and physical problems do not respond to various therapeutic approaches such as medication, physiotherapy, and psychotherapy, they are often called medically unexplained symptoms. As such, these symptoms are reported to be a response to stressful situations or emotional states, often unknown to patients themselves. To explore the effectiveness of noninvasive radioelectric brain stimulation in the amelioration of symptoms of pain and physical problems, we administered a neuropsychophysical optimization protocol using a REAC device.

Methods

The PSM, a self-administered questionnaire, was used to measure psychological stress and pain and physical problems in a group of 888 subjects. Data were collected immediately prior to and following a 4-week REAC treatment cycle.

Results

There was a significant reduction in scores measuring subjective perceptions of stress for subjects treated with one cycle of neuropsychophysical optimization REAC-BS. At the end of the study, the number of treated subjects reporting symptoms of stress-related pain and physical problems on the PSM test was significantly reduced, whereas there was no difference in placebo-treated subjects.

Conclusion

One cycle of neuropsychophysical optimization REAC-BS appears to reduce subjective perceptions of stress as measured by the PSM, particularly on the pain and physical problems cluster.