I am writing this post for my friend Michael.
Michael developed central pontine myelinolysis a few years ago. In the course of the past 18 months, he has seen a decline in his abilities. He has had ongoing issues with memory, attention, stuttering, movement issues (shakes, tremors, jerks, and spasms), and now he is having issues with mutism.
So, what is mutism? It’s the inability to speak, talk or make vocal noises. In some cases, this issue may be intermittent.
My friend has this issue. A few years after he suffered from central pontine myelinolysis, he began to have issues with mutism. He will go through periods of hours or days without being able to make any sounds. He is not even able to whistle.
I have shared this issue. My dysarthria varies in severity. Actually, some days it is barely noticeable. On other days, it’s difficult to communicate because of the stammering.
There does not seem to be any clear reason for the variations, but I have noticed that stress, fatigue, and even fluctuations in my medications can cause the issue. It does get worse when I have to figure out what I want to say, but if I have something that I’m reading from (reciting words), the problem is less significant. I do not have any scientific evidence as to why this happens but my guess is the way that the brain works at processing information. There must be different neurological pathways for reading out loud versus forming ideas and speaking. There is less thought process in reading words out loud from a page versus forming the words for an idea and speaking it.
I find this idea complex. It makes me pause to consider why it is.
Because of this brain injury, I have issues with getting ideas to mind at all, and at times those ideas seem to evaporate as soon as they form. So, there are periods where I do not have anything in my mind. I am desperately trying to think of something, but my mind is blank. Before I had a brain injury, ideas would just be there. I had a “quick wit”. There was far less thinking required. Sure, I would have to manipulate my ideas, the words the that I wanted to use to make my point, based on the audience, but the thought was there. Now, it takes a significant amount of time to just come up with a thought, to form the sentence, and then be able to communicate it effectively. It’s a rather daunting process when it no longer comes to you naturally.
Anyway, Michael’s issue with mutism developed recently, and is sporadic. So, is his condition unique?
One of the first articles that I found was in regards to children who have developed mutism after having cerebellar surgery. Now, this was interesting because central pontine myelinolysis is an injury that generally impacts the pons. The pons is extremely close to the cerebellum.
Because of the locality of the damage to the pons, I am going to suggest that the white matter of the cerebellum can also be impacted. So according to the following research article, it showed that there were children who would have sporadic mutism after damage to the cerebellum, “Cerebellar mutism syndrome and its relation to cerebellar cognitive and affective function: Review of the literature”. http://www.annalsofian.org/article.asp?issn=0972-2327;year=2010;volume=13;issue=1;spage=23;epage=27;aulast=Yildiz
Recent research studies suggest that neurological and cognitive impairments in CMS (cerebellar mutism syndrome) often persist. A prospective study evaluated the neurological status of patients 1 year post-diagnosis based on the presence and severity of ataxia, language difficulties, and other cognitive deficits.  Of the 46 patients who had postoperative CMS initially rated severe, residual deficits were common, including 92% with ataxia, 66% with speech and language dysfunction, and 59% with global intellectual impairment. Of the 52 patients with moderate CMS, 78% had ataxia, 25% had speech and language dysfunction, and 17% had global intellectual impairment. Thus, impairment in these domains was common and was also directly related to the severity of CMS. Riva and Giorgi have shown neuropsychological problems a few weeks after cerebellar tumor resection, and prior to further treatment such as radiotherapy or chemotheraphy.  Their results reveal a localization related pattern, with problems of auditory sequential memory and language processing after right-sided cerebellar tumor and deficits in spatial and visual memory after left-sided tumor. Lesions to the vermis led to post-surgical mutism, which evolved into speech and language disorders as well as behavioral disturbances ranging from irritability to those reminiscent of mutism. 
Now, there is a belief that these issues with mutism are psychological in nature due to the trauma of the event, like car accident. However, this is definitely not the case with Michael, and there has been additional research showing that children that have a stuttering problem, do have injuries in their brains that have been shown to cause this condition. So, it is my belief that if there is an injury significant enough to cause a coma, that it is more likely that it is not a psychological trauma causing the mutism, but an injury to the brain.
So, if that’s the case, then why does the person experience the mutism intermittently?
In the cases of CPM and EPM, I think it is very possible that the injury can progress. Now, this thought goes against the opinions of most medical doctors. Most medical doctors believe that the injury is static; however, in my opinion, it is not CPM/EPM directly causing the injury, but the immune response to the injury. (I would encourage you to review my beliefs on late onset symptoms of CPM/EPM and brain injuries). Basically, the bodies natural response to injury is repair. In my opinion, it does not matter if this injury occurs in your foot, your heart, or your brain. Your immune system sends up a repair “team” no matter where the injury occurs; however, unlike other areas of the body, the brain does not have any non functioning areas, and as the repairs occur more damage is done to surrounding tissue. It creates a slow and steady deterioration, and as in other major structures of the body, scar tissue forms.
This opinion would also explain why a person who is treated with plasmaphoresis after head trauma (including after CPM/EPM) improves with fewer long lasting effects. Generally, it has been shown in previous studies (previously documented in my blog), that in persons who were treated with auto immune disabling treatments, recovered if not fully, significantly.
I also believe that for those who have awoken from a coma with mutism for months or years after, but eventually regain the ability to speak, it is because the brain has healed or has created new neuro- pathways. The following article describes a girl that suffered from a coma and suffered from mutism for 10 months. Eventually, she regained her ability to speak, but she continued to have issues with speaking, cognitive issues, etc.
The patient initially presened as comatose. A period of mutism subsequent to the coma extended for ten months. Following this protracted period of mutism the child demonstrated rapid and unexpected recovery of functional communication skills, despite the persistence of higher level language deficits.
The following article has information that is about a girl that developed mutism after having an injury to the pons. (Bingo! There does seem to be a correlation and an explanation as to why Michael, who has lesions in his pons, has developed mutism.)
As she was extubated one week later, she was found to have right hemiplegia and muteness. MRI showed a T2- bright lesion on the tegmentum of the left midbrain down to the upper pons. Right vertebral angiography disclosed an intimal ¯ap with stenosis at the C3 vertebral level presumably caused by a fracture of
the right C3 transverse process later con®rmed in a cervical 3D-CT scan. Her muteness lasted for 10 days, after which she began to utter some comprehensible words in a dysarthric fashion. Her neurological de®cits showed improvement within 3 months of her admission. Transient mutism after brain stem infarction has not been reported previously. We discuss the anatomical bases for this unusual reversible disorder in the light of previous observations and conclude that bilateral damage to the dentatothalamocortical ®bers at the decussation of the superior cerebellar peduncle may have been responsible for her transient mutism.
Read more: http://www.springerlink.com/content/h952wk14rwd65798/
Another case of mutism after brain injury, however this person experienced relief with treatment of diazepam:
A 34-year-old woman with a severe closed-head injury had many impairments including apparent global aphasia. After a diazepam premedication for a motor point block she was heard to speak a few words. A trial of oral diazepam succeeded in restoring speech adequate to make her needs known, which persisted on a maintenance dose of 5 mg t.d.s. The possible diagnoses and reasons for this phenomenon are discussed. We suggest that diazepam may be useful in assessing speech in selected people with severe head injuries.
The following article is only available fully if you pay for it. However, according to the introduction, a woman developed delayed mutism after she had a brain injury caused by drug related issues:
A 49-year-old woman developed a catatonic mute state a few weeks after methadone overdose. Clinical, radiological and histological findings were consistent with toxic spongiform leukoencephalopathy, which adds a potentially deadly side-effect to a generally considered safe substitution for heroin……..
The inability to generate oral-verbal expression, despite normal comprehension of speech. This may be associated with BRAIN DISEASES or MENTAL DISORDERS. Organic mutism may be associated with damage to the FRONTAL LOBE; BRAIN STEM; THALAMUS; and CEREBELLUM. Selective mutism is a psychological condition that usually affects children characterized by continuous refusal to speak in social situations by a child who is able and willing to speak to selected persons. Kussmal aphasia refers to mutism in psychosis. (From Fortschr Neurol Psychiatr 1994; 62(9):337-44)
The next article describes a girl that had issues with stunts in her brain. Her injury also happened in the cerebellar and tracts in the brain stem. The following has a detailed explanation of the researchers belief why akinetic mutism (AK) occurs:
Actually, in the latter situation, AM seems to be related to lesions that occur along pathways that originate in the mesencephalon ([Fig. 6]) and project widely to dopamine receptors in the spinal cord, brainstem, diencephalon, corpus striatum, and mesiofrontal lobe. The resultant behavioral abnormality causes the patient to remain awake but unable to initiate motor activity in response to sensory stimuli. Pressure transmitted to the diencephalon from the hydrocephalus can cause AM. The underlying mechanism is believed to be damage to the periventricular monoamine projections in the thalamus and hypothalamus caused by the expansion of the third ventricular wall. This is the theoretical basis for use of a dopamine agonist in humans with AM, giving gratifying results.
In posterior fossa surgery, damage of the dentate nuclei is the main factor for AM. Fibers emanate from the damaged dentate nuclei through the superior cerebellar peduncles to the contralateral red nucleus and the thalamus and supplementary motor area connected by the dentatothalamocortical pathway ([Fig. 6]). As already mentioned, the supplementary motor area has proven necessary for the initiation of speech
In contrast to AM secondary to hydrocephalus, in which the injured pathways are dopaminergic and/or monoaminergic, in the cerebellar mutism, the neurotransmitters consist of glutamate and aspartate that are found in cerebellorubral and cerebellothalamic fibers, whereas some GABA-containing cells give rise to cerebellopontine and cerebello-olivary fibers. Some cerebelloreticular projections may also contain GABA.
Now, I found the following article extremely interesting. It describes brain injuries that occur due to lack of blood flow and/or lack of oxygen. Now, why I found this next article extremely interesting because it documents improvements in symptoms initially, but months to a year or more later, the person’s symptoms progress. This is the same type of progression that has been reported in those with chronic concussions, and the majority of those that I know with CPM/EPM. I believe that there is a connection that is not clearly understood at this time in regards to how the brain reacts to injury, and it can occur regardless of the injury. (HI stands for hypoxic- ischemic and BI stands for Brain Injury)
Delayed Post-Hypoxic Leukoencephalopathy
In rare cases, early and complete recovery from HI-BI is followed a few days to weeks later by a severe demyelinating syndrome; this syndrome, delayed post-hypoxic leukoencephalopathy, characterized by acute or subacute onset of severe and progressive neuropsychiatric problems such as delirium, psychosis, parkinsonism, and/or akinetic-mutism, and/or quadriparesis, among others. Although this condition is often described as a delayed sequelae of carbon monoxide-induced HI-BI, it has been associated with nearly all causes of HI-BI (Shprecher and Mehta 2010). The neural mechanisms of delayed post-hypoxic demyelination have not been established definitively. However, combinations of toxic exposure (e.g., carbon monoxide, inhaled heroin), genetic (e.g., pseudodeficiency of arylsulfatase A, abnormalities of other genes regulating myelin turnover), and age-associated vascular risk factors have been suggested as possible contributors to this unusual post-hypoxic condition. Regardless of mechanism, this syndrome is characterized neuropathologically by diffuse bihemispheric demyelination that generally spares the cerebellum and brainstem. Neurological and neurobehavioral improvement over the first 3 to 12 month periods following onset of this syndrome is typical, but many survivors experience persistent cognitive impairments (particularly impairments of attention, processing speed, and/or executive function), parkinsonism, and/or corticospinal tract signs. There are case reports describing symptomatic and functional improvement of the cognitive and parkinsonian sequelae of delayed post-hypoxic leukoencephalopathy during treatment with stimulants, amantadine or levodopa. The observation that these agents offer some benefit in this context despite their lack of efficacy for the same sequelae of HI-BI itself may reflect differences in the anatomy of these conditions: in HI-BI there is involvement of both gray and white matter, limiting the target of pharmacotherapies more severely than in delayed post-hypoxic leukoencephalopathy, which involves only white matter.
I have to say that this idea of mutism after brain injury is absolutely possible. It seems to be more studied in children who have experienced brain injuries vs adults. There seems to be some professionals who believe that it is a psychological issue and others that believe there is a neurological injury that causes it. I believe that you must rule out the physical injury before you consider the psychological cause. Keep in mind that it was only recently discovered that stuttering has a physical cause. This is because the brain is phenomenally complex, and we do not have the technological advancements nor the physical understanding to map the complexity of the brain. This means that you have to approach the subject with an open mind.
Despite the lack of information and understanding, there does appear to be a physiological link to the pons, the cerebellum, and possibly the basal ganglia and the ability to speak. It is also likely that not all of these injuries progress or heal at the same rate, which means that even after mild brain injuries there is a chance that mutism can develop or resolve.
I would HIGHLY recommend that after a brain injury, even mild brain injury, discuss the use of steroids (anti-inflammatory types of steroids that inhibit the immune system-not testosterone) or possibly plasmaphoresis. There has also been research that shows that hyperbariac oxygen exposure can also speed recovery and provide a better recovery. There seems to be a lot of scientific evidence that shows a person’s immune response is in part if not entirely responsible for late onset symptoms.
There will be more to come on this topic as I locate more information.
- Attention and Executive Functioning in Children with Chiari Malformation type I (udini.proquest.com)
- CDA teen with severe brain injury defies the odds (krem.com)
- AZ teen bounces back from brain injury (abc15.com)
- Towards a New Split-Brain Model: Up Brain / Down Brain (psychologytoday.com)
- AZ teen bounces back from brain injury (abc15.com)
- Towards a New Split-Brain Model: Up Brain / Down Brain (psychologytoday.com)