Brain Disorders: Electroconvulsive Therapy vs Transcranial Magnetic Stimulation.

Shock Therapy: A barbaric treatment no longer in use?
Previous treatments of mental illnesses are often now viewed as extreme. Back in the 1800’s the use of primitive treatment to cut away a section of the patient’s skull to release the ‘evil spirits’ from their body was a common treatment of mental disorders. A tranquilizing chair was also often adopted, where the individual would have to place their head inside a box to reduce blood flow to their brain (Griggs, 2014). Yes, this seems outrageous, terrifying and barbaric in today’s society. In modern day medicine however, the use of biomedical treatments such as electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS or rTMS) can actually be used to treat mental disorders, and have shown to be particularly successful in treatment-resistant depression. The unusual historical treatments have often led to the common misconception of ECT in that it is invasive and unsafe, however this is no longer viewed as the case.  These two approaches have actually revolutionized the treatment of depression, and now recent research also supports the use of TMS in those with autism and epilepsy, which will be discussed in this essay.

The History of Electroconvulsive Therapy
Italian neurologists Ugo Cerletti and Lucio Bini developed electroconvulsive therapy. Cerletti was an epilepsy specialist who knew that an electric shock across the head would lead to seizures. He thought that induced convulsions could be used to treat schizophrenia, however these convulsions were far too severe. Along with Kalinowski, a German physician, the researchers developed experiments to test brief electric shocks on humans. Around 10 – 20 ECT shocks on alternate days produced improvement in patients with acute-onset schizophrenia. Another side effect, which appeared to be beneficial, was the retrograde amnesia it caused, as it meant that patients did not report bad experiences towards the therapy. In further use, the treatment was found to be highly effective in depression (Sabbatini, 2016). Today ECT is executed under anesthesia, where small electrical currents are passed through the brain to specific areas via electrodes on the patient’s skull. This targeted therapy makes for an improvement on the previously used treatments such as drugs, as the side effects are minimal. The misconceptions associated with ECT were due to its improper use in its early days. It was often used to control psychiatric patients, whilst conscious and mostly without consent. Various media has depicted ECT in this way, such as the movie/novel One Flew Over the Cuckoos Nest – which is not how the treatment is used (Lilienfeld and Arkowitz, 2014).

ECT Success in Depression
ECT is currently one of the most successful therapies for severe depression, and sometimes in bipolar disorder, however less frequently in other mental disorders. In a meta-analysis by Pagnin et al (2004), ECT was shown to be the superior treatment in comparison to placebos, simulated ECT (a procedure were shocks are not given) and antidepressants, including tricyclic antidepressants and monoamine oxidase inhibitors. Tew et al (1999) found that even older patients with more severe depression and cognitive impairment could tolerate the use of ECT as equally as the younger patients with severe major depression, and even showed some improvement in results.

How does ECT work?
This is one thing we are unsure about, there are many theories postulated however the specific mechanisms leading to improvement in depressive disorders are unknown. It is possible that ECT increases the monoamine neurotransmitters, such as dopamine and serotonin, which are thought to be reduced in those with depression. Another theory is that the treatment stimulates the release of hormones from the hypothalamus or pituitary, as the hypothalamic-pituitary-adrenal axis is thought to be disturbed in depression. The treatment is also thought to have an anti-convulsant nature, rising the threshold for seizures and decreasing their duration. The final theory is that the efficacy of the treatment is due to an increase in synaptogenesis and neurogenesis.

Research by Madsen at al (2000) suggests that ECT leads to an increase in neurogenesis. Rats in this study were either given single electroconvulsive seizures, or a series of 10. Bromodeoxyuridine (BrdU) was administered to the rats; this is a marker commonly used to highlight newly born cells – an indicator of neurogenesis. This marker was used in combination with a specific neuronal marker and co-staining could therefore indicate these new cells were specifically neurons. One month following a single electroconvulsive seizure, there was a 3-fold increase in cells stained with BrdU in the dentate gyrus of the rat’s hippocampus (Figure 1), thus supporting the neurogenesis theory of ECT.

1

Figure 1: A single electroconvulsive seizure (ECS) stimulates cell proliferation. Double immunofluoroscence images showing a rat dentate gyrus from (top) a sham-treated animal and (bottom) an ECS treated-animal. Bromodeoxyuridine (BrdU) was injected six times with 12-hour intervals, starting 72 hours after ECS. Animals survived 1 month after the ECS treatment. Red cells are positive for the mitotic marker BrdU, and green cells are positive for the neuronal marker NeuN. Scale bar, 50 μm (Madsen et al 2000).

Transcranial Magnetic Stimulation: An advancement of ECT
TMS is another brain stimulation technique, which uses magnetic field (similar to that used in an MRI). It is non-invasive and unlike ECT the patients do not have to be under anesthesia. The magnetic currents pass through the brain and skull to induce currents in the brain tissue underlying a coil placed on the scalp of the individual. Similarly to ECT, TMS is a targeted therapy leading to fewer side effects than commonly used medications. This technique does have possible use as a therapeutic method, as it has been shown to be successful in depression. At the American psychiatric association’s annual meeting in 2013 they showed that TMS induced improvement in depression, and these results were maintained throughout the 12-month study, suggesting that the effects of TMS are long lasting. More recently however, TMS has been successfully used as a diagnostic tool for many disorders such as depression, epilepsy and autism (Narayana et al 2015). In epilepsy it has been used to determine the changes in the excitability of neurons in the brains of patients, and how this has altered after treatment with anti-epileptic drugs. TMS can then be applied to these epilepsy patients therapeutically as low-frequency TMS can reduce cortical excitability- it is a very promising treatment approach for people with treatment-resistant refractory epilepsy (Narayana et al 2015). Again, similarly to ECT the biology behind why TMS works is not completely understood. 

Autistic Spectrum Disorder – an upcoming use of TMS
Autistic Spectrum disorder has been considered a possible candidate for the therapeutic use of TMS. Autism affects around 700,000 people in the UK alone. It is a disorder that causes an individual to present with deficits in social interaction and communication across multiple contexts (according to DSM-5).  Advances within Neuroscience have allowed us to determine differences in the brains of those with autistic spectrum disorder, one such variation is that people with autism have larger brain sizes – possibly due to larger numbers of neurons. There is thought to be a lack of communication between various regions in the brain, which could explain why those with autism have difficulties integrating different cognitive functions. Although TMS has been used effectively in the treatment of depression, its use in autism is relatively novel and still being studied.

John Elder Robison, an individual with autistic spectrum disorder, was involved in a six-month study where he received weekly TMS treatments. He revealed that this treatment gave him empathy he had never felt before and the ability to perceive music in a way he had never experienced. To read more about John’s experience, his book ‘switched on’ is available, which details his use of TMS treatment and its effects.

Both of these techniques, ECT and TMS have been very successful in the treatment of depression, and particularly TMS as a diagnostic tool and potential therapeutic tool for many other brain disorders. These brain stimulation techniques hold many advantages over more commonly used treatments such as pharmacotherapy and unquestionably over the tranquilizing chair and primitive treatment. These treatments are not dangerous and could possibly change the way we diagnose and treat specific disorders, including autism, which there is currently few treatments for.

Author: Abbie Byford 

Editor: Molly Campbell

 

References

Griggs, R. 2014. Concise introduction to psychology. Worth Pub.

Sabbatini, R. 2016. The History of Shock Therapy in Psychiatry. Cerebromente.org.br. [Online].

Pagnin, D et al. 2004. Efficacy of ECT in Depression: A Meta-Analytic Review. The Journal of ECT. 20(1),pp.13-20.

Lilienfeld, S. and Arkowitz, H. 2014. The Truth about Shock Therapy. [Online].

Tew, J et al. 1999. Acute Efficacy of ECT in the Treatment of Major Depression in the Old-Old. Am J Psychiatry. 156(12),pp.1865–1870.

Madsen, T el al. 2000. Increased neurogenesis in a model of electroconvulsive therapy. Biological Psychiatry. 47(12),pp.1043-1049.

Narayana, S et al. 2015. Clinical Applications of Transcranial Magnetic Stimulation in Pediatric Neurology. Journal of Child Neurology. 30(9),pp.1111-1124.

https://www.autismspeaks.org/what-autism/diagnosis/dsm-5-diagnostic-criteria

http://www.npr.org/sections/health-shots/2016/04/21/475112703/electric-currents-and-an-emotional-awakening-for-one-man-with-autism

 

 

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