eTable 3. Grades of clinical severity in type 2 neurofibromatosis (NF2) The disease is categorized as moderate whenever its classification as either mild or severe seems clinically inappropriate.*¹.

Mild	Severe
Age at onset >30 years + no more than two further tumors (symptomatic or >1.5 cm)*2	Age at onset ≤ 20 years + at least two further tumors (symptomatic or > 1.5 cm) aside from the bilateral vestibular nerve schwannomas or demonstration of a tumor of the central nervous system before the 11th birthday and at least one further symptomatic tumor with positive genetic findings for NF2
– Retained good functional hearing – No dizziness – No impairment of verbal expression – No more than mild bilateral visual impairment – No more than mild gait impairment – No more than mild pain	– Total deafness – Incapacitating vertigo – Dysphagia necessitating tube feeding – Phonation disturbance – Severe visual impairment – Facial nerve palsy, HB grade 3 or worse – Wheelchair-bound because of paraparesis/paraplegia or severe ataxia – Incontinence necessitating catheterization – Severe orientation disturbance – Severe memory impairment – Additional conditions with moderate or severe manifestations (e.g., postoperative syringomyelia, pseudotumor cerebri due to venous sinus occlusion by a parasagittal meningioma, medically intractable depression) – Severe chronic pain

*¹ The listed disease manifestations are to be considered a starting point for the categorization of clinical severity. The assessment should be performed by an experienced physician and updated at each follow-up examination.

*² Including vestibular nerve schwannomas and tumors that have already been resected

HB, House and Brackmann