Biomedical subjects

L C Dann

Publications and source records attributed to L C Dann.

3 recordsLinked to original sources

PubMed1995

Resolution of Lhermitte's sign in multiple sclerosis by treatment with weak electromagnetic fields.

Lhermitte's sign, the occurrence of an electrical sensation passing down the back to the legs on flexion of the neck is a common and characteristic feature of multiple sclerosis (MS) which is related to spinal cord lesions affecting the posterior columns and cervical nerve roots. The Lhermitte's sign, which has been reported to occur at some time in up to 25% of MS patients, is seldom painful but is often a cause of distress to the patient and usually a marker of increased disease activity. Treatment with extracranial picotesla range pulsed electromagnetic fields (EMFs) has been found efficacious in the management of various MS symptoms including pain syndromes. The present communication concerns three MS patients in whom two brief applications of EMFs resulted in resolution of the Lhermitte's sign which emerged during a period of exacerbation of symptoms in one patient and during a prolonged phase of symptom deterioration in the other two patients. As the cause of the Lhermitte's sign is thought to result from the spread of ectopic excitation in demyelinated plaques in the cervical and thoracic regions of the spinal cord, it is hypothesized that the effects of EMFs are related to the reduction of axonal excitability via a mechanism involving changes in ionic membrane permeability. A systemic effect on pain control systems is also postulated to occur secondary to the effects of EMFs on neurotransmitter activity and pineal melatonin functions. This report underscores the efficacy of picotesla EMFs in the management of paroxysmal pain symptoms in MS.

Adult↗

PubMed1994

Weak electromagnetic fields attenuate tremor in multiple sclerosis.

It has been estimated that about 75% of patients diagnosed with multiple sclerosis (MS) have tremor which can be exceedingly disabling. The most common tremor observed in patients with MS is a cerebellar intention tremor ('kinetic tremor') although postural tremor ('static tremor') is also common and often extremely incapacitating. Currently there is no effective medical treatment for the tremor of MS which, in some severe cases, may be abolished by stereotactic thalamotomy. It was reported recently that extracranial application of brief AC pulsed electromagnetic fields (EMFs) in the picotesla (pT) range produced improvement in motor and cognitive functions in patients with MS. The present communication concerns three MS patients with a chronic progressive course of the disease (mean age: 39.3 +/- 8.3 years; mean duration of illness: 11.3 +/- 3.2 years) in whom brief external applications of pulsed EMFs of 7.5 pT intensity reduced intention and postural tremors resulting in significant functional improvement. The report suggests that these extremely low intensity EMFs are beneficial also in the treatment of tremors in MS and that this treatment may serve as an alternative method to stereotactic thalamotomy in the management of tremor in MS. The mechanisms by which EMFs attenuate the tremors of MS are complex and are thought to involve augmentation of GABA and serotonin (5-HT) neurotransmission in the cerebellum and its outflow tracts.

Adult↗

PubMed1992

Seasonal panic disorder: a possible variant of seasonal affective disorder.

The present communication concerns a 30 year-old female patient with panic disorder in whom panic attacks appeared to be seasonally-related. Characteristically, attacks were more frequent and severe during the months of October to May with spontaneous remissions during the months of June to September. Since 70% of patients with seasonal affective disorder (SAD), a variant of affective illness characterized by recurrent winter depressions with remissions in summer, suffer from anxiety disorders, we propose that seasonal panic disorder may be a variant of SAD. Since SAD is associated with phase delay of circadian rhythms, some forms of panic disorder may be related to phase instability of circadian rhythms. Moreover, since administration of artificial bright light therapy is currently the most effective treatment for SAD, it is suggested that patients with panic disorder should be questioned as to whether their symptoms are seasonally related. If a positive association is established, these patients should be offered treatment with light therapy prior to or coincident with the institution of pharmacotherapy.

Adult↗