Cerebellum: how accurate is your MS history?
When her records arrived, her verbal medical history bore no resemblance to what had been documented in her medical records.
Case study
On a superficial level, she seemed to be cognitively intact and gave a good account of her multiple sclerosis over the last twenty-odd years. However, when her records arrived, her verbal medical history bore no resemblance to what had been documented in her medical records. Her timing of events was widely off, and the landmarks, for example, when she had had significant relapses and had started and stopped specific disease-modifying therapies, were jumbled. It was as if her medical history had been written on a pack of cards, and somebody had shuffled the pack before our initial meeting.
The clue was in her neurological examination. She had what many call a cerebellar presentation, i.e., slurred speech, dancing eyes (nystagmus and square-wave jerks), unsteadiness of gait, an intention tremor, poor fine movement of her hands, and a particular type of cognitive impairment that is associated with cerebellar involvement.
Cerebellar cognitive impairment
I have previously done a post on the cerebellum and posterior fossa involvement in multiple sclerosis, which received a lot of attention and generated a lot of discussions (Q&As). If you haven’t read this newsletter, I suggest doing so before reading the remainder of this newsletter, which will concentrate on the cerebellum's role in cognition.
Has MS affected your brainstem and cerebellum? (1st-Oct-2021)
The traditional neurology teaching is that the cerebellum is mainly responsible for motor control hence the focus on limb coordination, gait, speech and eye movements. However, there is increasing recognition that the cerebellum is important in cognition and emotional control. Basic studies reveal that the so-called cerebral association areas on the brain's surface that subserve higher-order behaviour are linked with the lateral hemispheres of the posterior cerebellar lobe. These connections relay via nuclei of the pons and go back from the cerebellum to the cortex via the deep cerebellar nuclei via the thalamus. In addition, there are reciprocal connections between the cerebellum and the hypothalamus, an area of the brain that controls more primitive automatic behaviours such as sleep, appetite, sexual function, etc.
I know this is very complex, but these neuronal pathways show that cerebellar function is incorporated into widely distributed neural circuits that govern or control intellect, emotion and autonomic function in addition to the traditional role in sensory and motor control.
The clinical relevance of this is the observations of cognitive and psychiatric manifestations of cerebellar lesions, and the description of the cerebellar cognitive affective syndrome (CCAS) in patients with lesions confined to the cerebellum, including people with MS. These neurobehavioural deficits have been reported to even occur in the absence of the cerebellar motor signs, but in my experience, this is uncommon in people with MS.
The impairments associated with CCAS are typically in executive function (planning, set-shifting, verbal fluency, abstract reasoning, working memory), spatial cognition (visual-spatial organisation and memory) and linguistic processing (agrammatism and dysprosodia). Dysprosody is characterized by alterations in intensity, the timing of speech segments and the rhythm, cadency, and intonation of words. Agrammatism is a tendency to form sentences without the correct inflectional structure.
As I got to know this patient, it became apparent how disorganised her life was and how much she needed her husband to cope. In short, she had a form of dementia that is called cerebellar dementia. I say dementia because her cognitive problems were preventing her from working and were having a significant impact on her social functioning. Sadly, the deficits are irreversible due to the nature of her disease. Interestingly, she was coping with activities of daily living. At a superficial level, her motor impairments were not severe enough to prevent her from being relatively independent in these domains.
So why is it essential to identify cerebellar-related cognitive impairments? Firstly, it is associated with a poor prognosis. These patients need more help in managing and organising their lives. Often these patients don’t have much insight into these deficits, and when asked, they don’t complain of cognitive problems. Patients with cognitive impairment and cerebellar issues are more at risk of falls, road traffic and other accidents, forgetting to take their medication (poor adherence) and are vulnerable to being scammed by con artists. I recall one of my patients with this syndrome giving away most of his life savings to a dubious charity. Patients with this syndrome are known to have slow reaction times and should not be driving. If in doubt, they should have a detailed driving assessment before having their driving license renewed.
It has been suggested that MS HCPs create an at-risk patient register to give these patients and others more attention and help in the community. This is easier said than done, given the dire state of the NHS. However, with the new social prescribing budgets, these patients may be eligible for a community-based link worker if they don’t have someone to care for them. Sadly, many of these patients become socially isolated and need help.
I would be interested to know if any of you recognise these symptoms and whether or not cerebellar-associated cognitive impairment has ever been discussed with you in the clinic.
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General Disclaimer: Please note that the opinions expressed here are those of Professor Giovannoni and do not necessarily reflect the positions of Barts and The London School of Medicine and Dentistry nor Barts Health NHS Trust. The advice is intended as general advice and should not be interpreted as personal clinical advice. If you have problems, please tell your healthcare professional, who will be able to help you.
Yes I go to the gym a lot. It's only 10 minutes away, so I jog but that's getting harder as I approach my 9th decade. Still swimming as often possible all year round. It's probably keeping me reasonably well. Although some would say older pwMS don't have such active MS so it could just be anno domini.
I have had MS for a number of years and feel that going to the gym has aided my own cerebellum. Are there any other MS patients who often go to the gym as well?