I received a comment from Elle. She has vision issues too. She did research and feels that her ongoing vision issues are related to CPM and EPM and is classified as Visual Snow. I do not know much about Visual Snow, but I have to say, it is plausible that Central Pontine Myelinolysis and Extra Pontine Myelinolysis can cause this.
I do not know anything significant about Visual Snow, but there was mention that it is attributed to other demyelinating diseases such as MS. In essence, CPM/EPM are similar in that they both are conditions that effect the myelin. There is also a connection to visual snow and ocular and classic migraines. There also seems to be a connection in this and tinnitus.
Unfortunately, today is not a great vision day for me, and the more I try to read, the more I experience the blurriness of vision. (It is so frustrating!) I tried to access medical literature that described Visual Snow, but it seems under researched.
The following are pictures and videos in regards to what Visual Snow is like for those who have it.
Now, the visual condition that I experience is truly just blurry vision. (I do get ocular migraines though which started way before the brain injury.) Unlike the reports about Visual Snow, my blurry vision comes and goes. I had it earlier today, and now (about two hours later) it is gone again. It could come back in a few minutes or it might not come back at all. The blurriness can be slight or it can be extreme.
I did find a report of others with CPM and EPM who have experienced the blurry vision after injury.
A 40-year-old man presented with acute onset walking difficulty, slurred speech, and slight blurring of vision. Other relevant clinical history included chronic alcoholism and poor nutrition. Clinical examination revealed mild lower limb incoordination, dysarthria, and bilateral partial abducent nerve palsy. The blood tests for full blood count, renal functions (sodium, 142 mmol/L; potassium, 4 mmol/L; urea, 4.6 mg/dL; creatinine, 85 μmol/L), blood glucose (6.1 mmol/L), serum osmolality (285 mosm/kg), and liver function tests (albumin, 41 g/L; globulin, 25 g/L; bilirubin, 12 μmol/L; aspartate aminotransferase, 30 U/L; γ-gluta myltransferase, 45 U/L; and alkaline phosphate, 142 U/L) were within normal limits.
Another article explains the same symptoms in a woman (http://www.imj.ie/ViewArticleDetails.aspx?ContentID=3623):
A 41-year-old lady was woken up at 5am with sudden pins and needles and weakness involving the hands, trunk and legs. She had gone to bed completely well the previous night. When she attempted to rise, she was weak and unsteady. She then experienced blurred vision and had difficulty speaking and swallowing. Her symptoms worsened over the course of the day. She was transferred to UCHG after one day. On examination she was fully conscious but dysarthric. She had sluggish tongue movements with no palatal movements and severely impaired swallowing. She had abnormal eye movements identified as opsoclonus, upgaze restriction and bilateral partial ptosis. There was pyramidal weakness in both upper and lower limbs limbs, particularly in the right lower limb. Both knee jerks were pathologically brisk and the right plantar was extensor. Other deep tendon reflexes were normal. The upper and lower limbs were severely ataxic. Sensation was normal in all four limbs.
Another case believed to be caused by CPM/EPM (http://content.lib.utah.edu/utils/getfile/collection/EHSL-FBWNOC/id/599/filename/595.pdf):
The patient’s post-operative course was uneventful until 2 days after surgery when she noticed blurred vision in
both eyes and reported difficulty distinguishing colors.
Neuro-ophthalmic evaluation 5 days later disclosed 20/25 visual acuity at near in each eye. The pupils were equal
and reacted sluggishly to direct light. There was no relative afferent pupillary defect noted. The patient could read
only one of seven Ishihara color test plates with each eye. She could count fingers in her temporal visual fields but
could see only hand motions in her nasal visual fields. Dilated fundus exam was normal in each eye.
Automated visual field testing showed an incongruous, predominantly binasal, hemianopia………..We believe a demyelinating process, isolated extrapontine myelinolysis, caused our patient’s visual loss.
So, CPM and EPM can cause vision issues, and it has been noted in other patients that it can specifically cause blurred vision. I would not be surprised that it can cause a visual snow effect, but considering Visual Snow is just now being recognized as a symptom in the medical community, I doubt that there will be literature supporting it.
It is also not surprising that a person who experiences a head injury can experience vision changes. If a brain injury is caused by penetration of a foreign object, then it might obvious why a visual change occurs, but even in subtle head injuries, a person can experience a change in vision. There might be a structural change to your eye that causes the change, but there can also be change in the way your brain processes the neural impulses that causes visual disturbances.
This link provides insight to brain injury and visual changes: http://www.brainline.org/landing_pages/categories/vision.html
The following information describes how mild brain injuries, like concussions, can cause ongoing issues, including blurred vision:
As many as 30% of patients who experience a concussion develop postconcussive syndrome (PCS). PCS consists of a persistence of any combination of the following after a head injury: headache, nausea, emesis, memory loss, dizziness, diplopia, blurred vision, emotional lability, or sleep disturbances. Fixed neurologic deficits are not part of PCS, and any patient with a fixed deficit requires careful evaluation. PCS usually lasts 2-4 months. Typically, the symptoms peak 4-6 weeks following the injury. On occasion, the symptoms of PCS last for a year or longer. Approximately 20% of adults with PCS will not have returned to full-time work 1 year after the initial injury, and some are disabled permanently by PCS. PCS tends to be more severe in children than in adults. When PCS is severe or persistent, a multidisciplinary approach to treatment may be necessary. This includes social services, mental health services, occupational therapy, and pharmaceutical therapy. http://emedicine.medscape.com/article/433855-treatment
The following describes that there seems to be a connection to those who have a cognitive impact after a brain injury to visual complications:
Vision problems and cognitive deficits may compound one another. The most common complaints related to visual problems associated with brain injuries include light sensitivity, headaches, double vision, fatigue, dizziness, difficulty reading, or loss of peripheral visual fields. You may feel a heightened sensitivity to light and may even need to wear your sunglasses inside. You may have to request that fluorescent lights be turned off. Computer and reading tasks may take longer than usual, and tend to be more confusing and tiring. http://www.brainlinemilitary.org/content/2009/11/recovering-from-mild-traumatic-brain-injury_pageall.html
So again, there does seem to be a parallel in brain injuries in general, and more specific conditions and diseases like MS, CPM and EPM. In other words, no matter if you suffered from a physical brain injury, a concussion, or have a brain disease or syndrome, the symptoms are comparable.
Hope that helps folks!