Spreading depolarisation (SD): a potential underlying mechanism in functional neurological disorder (FND) 2025 Carlson et al

[Andy]

Abstract​

Functional neurological disorder (FND) presents with neurological symptoms lacking a structural correlate and is thought to result from brain network dysfunction. Despite advances in understanding its pathophysiology, several knowledge gaps exist. Spreading depolarisations (SDs), waves of cortical electrical disturbance best known in migraine aura and implicated in conditions like stroke and traumatic brain injury, have not been investigated in the context of FND.

We present a patient with recurrent episodes of limb weakness and speech disturbances initially diagnosed as FND. Years later, following a left superficial temporal artery–middle cerebral artery bypass, she developed similar symptoms. Intraoperative electrocorticography revealed SDs coinciding with symptom onset, and treatment with SD inhibitors led to clinical improvement. While further studies are needed to establish causality, this case highlights SD’s as a plausible pathophysiological mechanism in a subset of patients with FND and underscores the need for future research exploring their contribution to FND symptoms.

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[Snow Leopard]

This is interesting, but it contradicts it being "FND" if it is caused by https://en.wikipedia.org/wiki/Cortical_spreading_depression

 

[Utsikt]

Functional neurological disorder (FND) presents with neurological symptoms lacking a structural correlate and is thought to result from brain network dysfunction.

I wonder how they propose that the «brain network» can become dysfunctional without structural changes at some level?

 

[Yann04]

I wonder how they propose that the «brain network» can become dysfunctional without structural changes at some level?

Isn’t the “brain network” (seems like a vague term for neuronal connections like synapses and the like?) by definition structural?

 

[Utsikt]

Isn’t the “brain network” (seems like a vague term for neuronal connections like synapses and the like?) by definition structural?

Yes.

They might mean that the wires (i.e. the dendrites of the neurons) are getting tangled up in a complete mess although the wires still work the way they are supposed to, but that’s still a structural problem (with a physical cause of the mess).

If they mean without damage to individual neurons when they say «structural», then they are just using an inappropriate word because structural means more than just relating to individual neurons.

If they think that there exists something other than the physical, then they might as well say it outright: that they are dualists.

 

[Sean]

Functional neurological disorder (FND) presents with neurological symptoms lacking a structural correlate and is thought to result from brain network dysfunction. Despite advances in understanding its pathophysiology, several knowledge gaps exist.​

The main one being the mystery of how the FND advocates are able to avoid dealing with this contradiction, and the full implications of it.

If they called it Unexplained Medical Phenomenon - No. 7391, we would at least have an honest starting point for investigation and discussion.

 

[Utsikt]

Functional neurological disorder (FND) presents with neurological symptoms lacking a structural correlate and is thought to result from brain network dysfunction. Despite advances in understanding its pathophysiology, several knowledge gaps exist.​

The main one being the mystery of how the FND advocates are able to avoid dealing with this contradiction, and the full implications of it.

If they called it Unexplained Medical Phenomenon - No. 7391, we would at least have an honest starting point for investigation and discussion.

They are very good at doublethink.