Prof. Dr. J. Grotenhuis became Doctor of Medicine in October 1979. Training in neurosurgery from March 1981- March 1987. Board examination and certification in Germany in April 1987 and board certification in The Netherlands in July 1987. 1987-1995 staff member at assistant-professor level; 1995 associate professor. Since 1999 chairman. Since 2001 full clinical professor.
He is author of 77 peer-reviewed articles, 23 book chapters, and 2 (single-authored) books on endoscopic neurosurgery. He gave more than 250 international lectures (more than 100 as invited lecturer).
He is active in national and international neurosurgical organizations (e.g. Chairman of the national legal expertise committee, member of the accreditation committee, chairman of the EANS Postgraduate Education Committee, member of the EANS Training Committee, second national delegate to the WFNS)
His special interests are minimally invasive techniques (especially endoscopic neurosurgery) and instrument development, pituitary surgery, vascular neurosurgery, microvascular decompression; CSF dynamics, hydrocephalus, Chiari malformations and syringomyelia.