Clemastine reverses brain fog and white matter damage

Neuroscience researchers in China have concluded that a repurposed antihistamine drug, Clemastine, is capable of rescuing cognitive function caused by white matter damage due to chemotherapy; remyelination, oligodendrocyte differentiation and the increase of neurofilament protein by Clemastine could reduce temporary brain fog, and even more serious damage.

Brain fog, white matter damage and chemotherapy

Chemotherapy is often blamed by patients for causing Brain Fog, a term that refers to problems such as forgetfulness, mental fogginess, poor attention and memory, and poor decision-making issues that occur during and after cancer treatment. It can extend to poor motor skills and finding multi-tasking harder. It is thought to be linked to chemotherapy because many drugs can fully or in part, cross the blood brain barrier. Cleveland Clinic refer to Brain Fog as ‘Chemo Brain’ (1). However, they say it also may be due a secondary effect, for example, to hormone disruption, poor sleep, stress, fatigue, depression, gut problems or immune system changes. And they say most Brain Fog is temporary. 

This is, of course, a highly controversial subject.

However, chemotherapy is known to damage your white matter (2). An Australian review of Chemotherapy damage, talked of ‘highlighting the importance of implementing behavioural and pharmacological strategies to prevent or reverse such acute toxicity in the brain’.

What is white matter? If your brain is called your grey matter, the white matter is the nerve fibres that connect all your nerve cells. The nerves are surrounded by a protective insulation - a white myelin sheath. Hence the name. The myelin also helps speed up all messages travelling in the fibres. Grey matter and white matter are equally represented in your brain. 

Animals can develop white matter disease. For example, damage (lesions) can lead to cognitive impairment and even Dementia and Alzheimer’s. Blood flow deficiencies can lead to white matter hyperintensities. They show up on MRIs and these white areas are associated with an increased risk of stroke. Research from Japan (3) has shown that, despite various claims about chemotherapy increasing risk of stroke, it is more likely that the actual cancer is the cause, not the chemotherapy.

A study (4)  from Taiwan looking at the use of Oxaliplatin, had previously concluded that stroke risk was a combined 'cancer plus chemo' effect. 

White matter disease can also be linked to aging, high blood pressure, smoking and cardiovascular disease. Exercise and particularly weight training along with a Rainbow Diet have all been shown to improve your white matter.

Cimastine rescues cognitive function

Now comes a new study for treating Brain Fog - or is it White Matter damage? The study is entitled: Clemastine Rescues Chemotherapy-Induced Cognitive Impairment by Improving White Matter Integrity (5)

Clemastine is an H1 antihistamine. It had previously been shown by researchers from UCSF and Cambridge University (6) to enhance white matter myelin integrity in a mouse study in hypoxic (low oxygen) damaged brain conditions, but had never be researched in situations involving chemotherapy.

In the latest research, with mice, Clemastine caused significant regeneration of the myelin sheath and improved the animals’ cognitive function following chemotherapy treatment. Clemastine also promoted oligodendrocyte precursor cell differentiation and increased the neurofilament 200 protein levels in the corpus callosum and hippocampus. 

The researchers concluded that clemastine was capable of rescuing cognitive function damage caused by chemotherapy through improving white matter integrity. 

This study surely also ends any debate about the dangers of chemotherapy to the brain.

Go to: 10 ways to improve your chemotherapy and reduce side-effects

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References

1. Cleveland Clinic: Chemo brain - https://my.clevelandclinic.org/health/diseases/21032-chemo-brain

2. Chemotherapy-induced cognitive impairments: White matter pathologies; A Matsos, M Loomes, I Zhou, E Macmillan, I Sabel, E Rotziokos, W Beckwith, I N Johnston; Cancer Treat res; 2017 Dec;61:6-14.

3. The Effect of Chemotherapy on Stroke Risk in Cancer Patients; Takaya Kitano, Tsutomu Sasaki, Yasufumi Gon, Kenichi Todo et al;  Thromb Haemost, 2020 Apr;120(4):714-723.

4. Incidence of ischemic stroke post-chemotherapy: a retrospective review of 10,963 patients; Shau-Hsuan Li,  Wei-Hsi Chen et al; Clin Neurol Neurosurg; 2006 Feb;108(2):150-6.

5. Clemastine Rescues Chemotherapy-Induced Cognitive Impairment by Improving White Matter Integrity; Yingxi Chen, Jie Sheng, Xiuying Tang, Yuhong Zhao, Shujuan Zhu, Qian Liu; Neuroscience; 2022 Feb 21;484:66-79.

6. Clemastine rescues myelination defects and promotes functional recovery in hypoxic brain injury; Bruce A C Cree et al; Brain Jan 1;141(1):85-98.