Clinical Neurophysiology in Iceland

Neurophysiology Plus eBulletin

9 of August 2018

VAFO Project Iceland: P300, P50 and QEEG, objective neurophysiological measurements of brain activity were successfully acquired with dense array 256 channel EEG system at the Icelandic Center for Neurophysiology, Department of Biomedical Engineering, Reykjavík University (here)

1-6 May 2018

Clinical Neurophysiology Unit of Landspitali participated to the 31st International Congress of Clinical Neurophysiology (ICCN) of the International Federation of Clinical Neurophysiology (IFCN) in Washington, DC, USA with the work "Intraoperative recording of somatosensory evoked potentials from both peripheral median nerve and proximal upper trunk to assess C5, C6 brachial plexus injury" (here)

16 of March 2018

Intramedular tumor C6-T8 Intraoperative Neuromonitoring (here)

26 of February 2018

Right cerebellopontine angle (CPA) mass intraoperative neuromonitoring (here)

18 of January 2018

ANT Neuromeeting Beaune, Burgundy France. Study proposal and critical view: BNN assessment with TEPs (here)

20 of November 2017

Neurophysiology Plus group is represented at TMS workshop in Denmark: TMS-EEG modality related to an *Icelandic clinically applied proposed study* for patients with brain tumors and symptomatic epilepsy located in eloquent brain areas is critically analyzed during a TMS workshop in Denmark (here).

02 of November 2017

TMS Neuronavigation in Iceland: The neuronavigated transcranial magnetic stimulation (neuronavigated-TMS) was initiated with a pilot study of a healthy subject on 1st of November 2017 to find motor "hot-spots" and "speech area" (by inducing the speech arrest) in total relaxation and safety (here). This technique is used extensively for preoperative mapping of eloquent areas before craniotomy.

29 of September 2017

TMS-EEG evoked potentials, joint meeting of Clinical Neurophysiology expert team with Dr Paolo Gargiulo, Assist Prof in Reykjavik University. We tried to connect Medtronic multichannel amplifier (IONM Nim-Eclipse) with TMS Dantec to assess RMT of right APB in order to perform TMS-EEG evoked potentials (TEPs). Video-report (on the front page) was recorded by Egill Axfjörður Friðgeirsson, PhD student in Amsterdam, Netherlands working on the field of functional connectivity and deep brain stimulation (DBS). Abstract submitted to ANT Neuromeeting 2018 (clinical research proposal study and critical view)

4 of September 2017

Guyon Type II Syndrome (pure motor) was diagnosed today in our laboratory of electromyography in a 72 year-old male with weakness in the right hand and right FDI artrophy for more than 6 months (Case report)

26 of July 2017

Mixed silent period (MSP) and cutaneous silent period (CSP) in diagnostic of a severe carpal tunnel syndrome (severe CTS)

Cutaneous silent period can be preserved in entrapment neuropathies (KofIer et al 2003). It is known that the more severe the neuropathy is, the more impairment of A-delta fibers can be found (Duarte et al 2016). In patient with severe CTS the mean onset latency was increased to 85.0 ms (SD 8.7 ms, P < 0.01) Silvpauskaite et al 2005.

CASE REPORT Patient 66 year-old with motor weakness in hands and hypoesthesia

After we diagnosed very severe CTS in the right side and severe CTS in the left we performed A-delta & alpha motorneurons driven CSP from 2 digit and there was no clear inhibition of the voluntary contraction (onset 107ms). Then, we checked again from the palm-thenar region and we observed CSP with onset 100ms, end 155 ms and 55ms duration. Also a clear silent period was obtained after stimulation from the wrist, the mixed median nerve and record from abductor pollicis brevis.

Conclusion: Sensory fibers (small and fast) are the last in be damaged and the injury do not occurred at the wrist carpal tunnel as it happened with axonal loss of the large sensory fibers. At this moment there is not clear if those fibers are only the A-delta or there might be another sensory input by direct electrical stimulation of other fiber type (proprioceptors?, muscle spindles?)

20 of July 2017

Repetitive Transcranial Magnetic Stimulation (rTMS); Experimental research for Intractable Catastrophic Tinnitus

In Iceland, our first patient started the 10 sessions treatment with 1200 daily pulses 100%RMT applied in 60 series of 20 pulses (1Hz frequency) on 17th of July 2017. Location of coil was set to stimulate between T3 and C3/T5 using 10-20 international EEG system (Lee H.Y. et al 2013).

We use the same protocol used in Department of Otorhinolaryngology - Head and Neck Surgery, Kyung Hee University School of Medicine, Seoul (Lee H.Y. et al 2013, Clinical and Experimental Otorhinolaryngology Vol. 6, No. 2: 63-67, June 2013). To assess the progression of a possible rTMS effect on tinnitus perception we used Tinnitus Handicap Inventory THI questionnaire and Visual Analogue Scale for both tinnitus annoyance and loudness (here).

6 of April 2017

Repetitive Transcranial Magnetic Stimulation (rTMS) in Iceland; Mood Depressive Disorder and Chronic Neuropathic Pain

Few years ago, in 2004 and 2005 in Landspítali Fossvogur Iceland, Sigurjón Stefánsson and Anna L. Þórisdóttir started to use rTMS for patients with unipolar major depressive episodes on clinical research program. The aim was to investigate the effectiveness using a placebo-controlled crossover design to evaluate the antidepressant efficacy of 5 days of left prefrontal 10 Hz rTMS. They controlled the patients with changes in depressive symptoms and with P300 wave (auditory ERP) as a measure of concomitant changes in brain functioning (Möller et al 2006) (here). The amplitude of the auditory P300 wave has been found to be reduced in patients with depression and Sigurjón and Anna used it as an objective measure together with Hamilton scale. There was a decrease in the Hamilton depression scores after 5 days of active left prefrontal transcranial magnetic therapy. This apparent improvement did, however, not reach the significant level when compared with the results of similar placebo treatment. No correlation was found between changes in P300 amplitude and the Hamilton score, suggesting the rTMS effects on the P300 are unrelated to changes in depressive symptoms. The authors stated that the P300 increased after real rTMS but after sham there was no significant differences probably because this protocol was used after 4 weeks of the real treatment and the P300 was already modified by the treatment.

rTMS of the DLPFC can be proposed as a relevant technique to treat drug-resistant major depression, except for depression with psychotic features for which the use of ECT is recommended as the first-line adjunctive treatment. The recommendations on the use of rTMS in the treatment of mood disorders, Lefaucher et al 2014 (here) are consistent with those of CANMAT (Canadian Network for Mood and Anxiety Treatments) clinical guidelines, Kennedy et al, 2009 (here).

Nowadays, according to Anna & Sigurjón ´s original work conclusions (that 5 days are not enough to produce effects in depressive symptoms) the rTMS for MDD patients reached Level 1 evidence as second-line treatment with increased number of the daily sessions up to 10 or 20 with similar HF protocols.

Facial Chronic Neuropathic Pain and rTMS

Today rTMS returned to Iceland as an alternative for patients with central chronic neuropathic pain (here). Review of implantable pulse generator and motor cortex stimulation for FCNP by Monsalve 2012 can be reached here or another one with guidelines for rTMS by Lefaucher et al 2014 here. Other review we consider useful by Klein et al 2015 can be reached here. We are using Visual Analogue Scale to assess the rTMS efficacy.

20 of January 2017

Bereitschaftspotential used for neurophysiological assessment of apparent spinal spontaneous myoclonus. Patient with abdominal stereotyped jerks (Case Report here).

18 of January 2017

Using of one cortical 8 contacts strip electrode for IONM corticography, direct cortical MEP and SSEP in awake surgery. Cortical excitability was assessed inter-hemispherical with resting motor threshold obtained by using trans-cranial magnetic stimulation (Case Report here).

9 of January 2017

Preoperative motor and speech mapping using TMS. Cortical eloquent areas and their interconnected circuitry in patients with growing brain tumors and surgical removal indication are represented by disturbed biological neural networks. These networks need an integrated assessment due to their potential associated symptomatic epileptic syndromes and modified structure. To avoid new devastating neurological postoperative deficit functional anatomy holistic approach became a very useful instrument. This include motor, visual or speech eloquent areas identification and is used to identify and characterize the structures and neurological pathways which would permit an optimal surgical procedure. First study in Iceland was performed with Physiologist and Psychologist Anna L Þórisdóttir on 9th and 11th of January 2017 (Case Report here). We were able to determine motor hot-spots of bilateral APB and lower limbs. Speech naming test was performed using HF 15Hz and 2 or 1 second duration trials, assistants: Njáll Ingi Dalberg (MD) and Aron Dalin Jónasson (CN technician, Naturalist). Speech arest was obtained during second examination.

21 of December 2016

Trancranial Magnetic Stimulation technique could be reintroduced in Neurophysiology Laboratory Landspítali Fossvogur, Iceland. Neurophysiology Plus group and Staff from Neurology Department will open two specific practical and learning programs with Intracortical dynamics studies using single pulse and paired pulse paradigms but also with Cortical Silent Period. TMS will be used to assess diagnosis in myelopathic syndromes and pelvic floor dysfunctions (neuropathies, urinary incontinence, constipation, etc.) beside the functional and neurological examination.

14 of December 2016

Cutaneous Silent Period and Isometric Exercise on first dorsal interosseous (FDI) muscle project was continued today by Neurophysiology Plus group. We now performed the tests in 5 Healthy subjects using stimulation from both ulnaris and median nerves to the correspondent abductor pollicis brevis (APB) and FDI muscles, but also in a crossed manner from 3rd digit and recording from ulnaris FDI or 5th digit and recording from APB. Two exercise were performed: isometric and isocinetic FDI during 5 minutes.

The team of this work include external medical students to Neurology Department Landspitali Reykjavik Xiao Chun Ling (Taipei, Taiwan), Joaquín Soto Guerrero (Santiago de Chile, Chile), neuroscience Madrid & Reykjavik Universities MSc student Pablo Botella Lucena (Valencia, Spain), Physiotherapist Anna Maria Urban (Poland) and Clinical Neurophysiologist Ovidiu C. Banea (Sibiu, Romania). In summer 2016, we started to collect data on general basis and tried to guide our hypothesis.

9 of December 2016

Narcolepsy, Approximation to diagnostic, Multiple Sleep Latency Test (MSLT) by Ovidiu C. Banea (here)

1 of December 2016

First awake surgery in Iceland, Left frontal lobe space-occupying lesion, 41/35 mm in diameter. (here)