13.1.1 Trigeminal neuralgia

Benoliel R, Eliav E, Sharav Y. Self-reports of pain-related awakenings in persistent orofacial pain patients. J Orofac Pain 2009; 23: 330-338.

Cruccu G, Finnerup NB, Jensen TS, Scholz J, Sindou M, Svensson P, Treede R-D, Zakrzweska JM, Nurmikko T. Trigeminal neuralgia: new classification and diagnostic grading for clinical practice and research. Neurology 2016; 87: 220-228.

Di Stefano G, Maarbjerg S, Nurmikko T, Truini A, Cruccu G. Triggering trigeminal neuralgia. Cephalalgia 2017 Jan 1:333102417721677. doi: 10.1177/0333102417721677 [Epub ahead of print].

Drangsholt M, Truelove E. Trigeminal neuralgia mistaken as temporomandibular disorder. J Evid Base Dent Pract 2001; 1: 41-50.

Fromm GH, Graff-Radford SB, Terrence CF, Sweet WH. Pre-trigeminal neuralgia. Neurology 1990; 40: 1493-1495.

Haviv Y, Khan J, Zini A, Almoznino G, Sharav Y, Benoliel R. Trigeminal neuralgia (part I). Revisiting the clinical phenotype. Cephalalgia 2016; 36; 730-746.

Koopman JSHA, Dieleman JP, Huygen FJ, de Mos N, Martin CGM, Sturkenboom MCJM. Incidence of facial pain in the general population. Pain 2009;147:122-7

Mueller D, Obermann M, Yoon MS, et al. Prevalence of trigeminal neuralgia and persistent idiopathic facial pain: A population-based study. Cephalalgia 2011; 31: 1542–1548.

Obermann M, Yoon MS, Ese D et al. Impaired trigeminal nociceptive processing in patients with trigeminal neuralgia. Neurology 2007; 69: 835-841.

Pareja JA, Cuadrado ML, Caminero AB, Barriga FJ, Baron M, Sanchez-del-Rio M. Duration of attacks of first division trigeminal neuralgia. Cephalalgia 2005; 25: 305-308.

Rasmussen P. Facial pain. II. A prospective survey of 1052 patients with a view of: character of the attacks, onset, course, and character of pain. Acta Neurochir (Wien) 1990; 107: 121-128.

Rasmussen P. Facial pain. III. A prospective study of the localization of facial pain in 1052 patients. Acta Neurochir (Wien) 1991; 108: 53-63.

Rasmussen P. Facial pain. IV. A prospective study of 1052 patients with a view of: precipitating factors, associated symptoms, objective psychiatric and neurological symptoms. Acta Neurochir (Wien) 1991; 108: 100-109. Classical trigeminal neuralgia

Antonini G, Di Pasquale A, Cruccu G, et al. Magnetic resonance imaging contribution for diagnosing symptomatic neurovascular contact in classical trigeminal neuralgia: a blinded case-control study and meta-analysis. Pain 2014; 155: 1464-1471.

Bowsher D, Miles JB, Haggett CE, Eldridge PR. Trigeminal neuralgia: a quantitative sensory perception threshold study in patients who had not undergone previous invasive procedures. J Neurosurg 1997; 86: 190-192.

Leal PR, Barbier C, Hermier M, Souza MA, Cristino-Filho G, Sindou M. Atrophic changes in the trigeminal nerves of patients with trigeminal neuralgia due to neurovascular compression and their association with the severity of compression and clinical outcomes. J Neurosurg 2014; 120: 1484-1495.

Maarbjerg S, Wolfram F, Gozalov A, Olesen J, Bendtsen L. Significance of neurovascular contact in classical trigeminal neuralgia. Brain 2015; 138: 311-319. Secondary trigeminal neuralgia

Cheng TM, Cascino TL and Onofrio BM. Comprehensive study of diagnosis and treatment of trigeminal neuralgia secondary to tumors. Neurology 1993; 43: 2298-2302.

Coffey RJ, Fromm GH. Familial trigeminal neuralgia and Charcot-Marie-Tooth neuropathy. Report of two families and review. Surg Neurol 1991; 35: 49-53.

Cruccu G, Biasiotta A, Di RS, et al. Trigeminal neuralgia and pain related to multiple sclerosis. Pain 2009; 143: 186-191.

De Paula Lucas C, Zabramski JM. Dural arteriovenous fistula of the transverse-sigmoid sinus causing trigeminal neuralgia. Acta Neurochir 2007; 149: 1249-1253.

O’Connor AB, Schwid SR, Herrmann DN, et al. Pain associated with multiple sclerosis: systematic review and proposed classification. Pain 2008; 137: 96-111.

Tanaka BS, Zhao P, Dib-Hajj FB, Morisset V, Tate S, Waxman SG, Dib-Hajj SD. A gain-of-function mutation in Nav1.6 in a case of trigeminal neuralgia. Mol Med 2016; 22: 338-348.

Truini A, Prosperini L, Calistri V, et al. A dual concurrent mechanism explains trigeminal neuralgia in patients with multiple sclerosis. Neurology 2016; 86: 2094-2099.

Wei Y, Zhao W, Pu C, et al. Clinical features and long-term surgical outcomes in 39 patients with tumor-related trigeminal neuralgia compared with 360 patients with idiopathic trigeminal neuralgia. Br J Neurosurg 2017; 31: 101-106.

Yip V, Michael BD, Nahser HC, Smith D. Arteriovenous malformation: a rare cause of trigeminal neuralgia identified by magnetic resonance imaging with constructive interference in steady state sequences. QJM 2012;105:895-898. Idiopathic trigeminal neuralgia

Lee A, McCartney S, Burbidge C, Raslan AM, Burchiel KJ. Trigeminal neuralgia occurs and recurs in the absence of neurovascular compression. J Neurosurg 2014;120:1048-1054. Painful trigeminal neuropathy attributed to herpes zoster

Dworkin RH, Portenoy RK. Pain and its persistence in herpes zoster. Pain 1996; 67: 241-252.

Haanpää M, Dastidar P, Weinberg A, Levin M, Miettinen A, Lapinlampi A-M, Laippala P, Nurmikko T. Characteristics of cerebrospinal fluid and magnetic resonance imaging findings in patients with acute herpes zoster. Neurology 1998; 51: 1405-1411.

Liesegang TJ. Herpes zoster ophthalmicus. Natural history, risk factors, clinical presentation, and morbidity. Ophthalmology 2008; 115 (2 Suppl): S3-12. Trigeminal post-herpetic neuralgia

Alvarez FK, de Siqueira SR, Okada M, et al. Evaluation of the sensation in patients with trigeminal post-herpetic neuralgia. J Oral Pathol Med 2007; 36: 347-350.

Truini A, Galeotti F, Haanpää M, et al. Pathophysiology of pain in postherpetic neuralgia: A clinical and neurophysiological study. Pain 2008; 140: 405-410.

Truini A, Haanpää M, Provitera V, et al. Differential myelinated and unmyelinated sensory and autonomic skin nerve fiber involvement in patients with ophthalmic postherpetic neuralgia. Front Neuroanat 2015; 9: 105. Painful traumatic trigeminal neuropathy

Benoliel R, Birenboim R, Regev E, Eliav E. Neurosensory changes in the infraorbital nerve following zygomatic fractures. Oral Surg 2005; 99: 657-665.

Benoliel R, Zadik Y, Eliav E and Sharav Y. Peripheral painful traumatic trigeminal neuropathy: Clinical features in 91 cases and proposal of novel diagnostic criteria. J Orofac Pain 2012; 26: 49-58.

Jääskeläinen S K, Teerijoki-Oksa T and Forssell H. Neurophysiologic and quantitative sensory testing in the diagnosis of trigeminal neuropathy and neuropathic pain. Pain 2005; 117: 349-357.

Polycarpou N, Ng YL, Canavan D, et al. Prevalence of persistent pain after endodontic treatment and factors affecting its occurrence in cases with complete radiographic healing. Int Endod J 2005; 38: 169-178.

Queral-Godoy E, Figueiredo R, Valmaseda-Castellon E, Berini-Aytes L, Gay-Escoda C. Frequency and evolution of lingual nerve lesions following lower third molar extraction. J Oral Maxillofac Surg 2006; 64: 402-407.

Renton T and Yilmaz Z. Profiling of patients presenting with posttraumatic neuropathy of the trigeminal nerve. J Orofac Pain 2011; 25: 333-344. Painful trigeminal neuropathy attributed to other disorder

Cruccu G, Penisi EM, Antonini G, et al. Trigeminal isolated sensory neuropathy (TISN) and FOSMN syndrome: despite a dissimilar disease course do they share common pathophysiological mechanisms? BMC Neurol 2014; 14: 248.

Klasser GD, Balasubramaniam R, Epstein J. Topical review—Connective tissue diseases: Orofacial manifestations including pain. J Orofac Pain 2007; 21: 171-184

13.2.1 Glossopharyngeal neuralgia

Blumenfeld A, Nikolskaya G. Glossopharyngeal neuralgia. Curr Pain Headache Rep 2013; 17: 343.

Huynh-Le P, Matsishima T. Hisada K. Matsumoto K. Glossopharyngeal neuralgia due to an epidermoid tumour in the cerebellopontine angle. J Clin Neurosci 2004; 11: 758-760.

Kandan SR, Khan S,. Jeyaretna DS, Lhatoo S, Patel NK, Coakham HB. Neuralgia of the glossopharyngeal and vagal nerves: long-term outcome following surgical treatment and literature review. Br J Neurosurg 2010; 24: 441-446.

Minagar A, Sheremata WA. Glossopharyngeal neuralgia and MS. Neurology 2000; 54: 1368-1370.

Patel A, Kassam A, Horowitz M, Chang YF. Microvascular decompression in the management of glossopharyngeal neuralgia: Analysis of 217 cases. Neurosurgery 2002; 50: 705-710.

Peet MM. Glossopharyngeal neuralgia. Ann Surg 1935; 101: 256-258.

Saman Y, Whitehead D, Gleeson M. Jugular foramen schwannoma presenting with glossopharyngeal neuralgia syncope syndrome. J Laryngol Otol 2010; 124: 1305-1308.

Tanrikulu L, Hastreiter P, Dorfler A, Buchfelder M, Naraghi R. Classification of neurovascular compression in glossophgaryngeal neuralgia: three-dimensional visualiztion of the glossopharyngeal nerve. Surg Neurol Int 2015; 6: 189.

13.2.2 Painful glossopharyngeal neuropathy

Bakar B. The jugular foramen schwannomas : Review of the large surgical series. J Kor Neurosurg Soc 2008; 44: 285-294.

Kalladka M, Nasri-Heir C, Eliav E, Ananthan S, Viswanath A, Heir G. Continuous neuropathic pain secondary to endoscopic procedures: report of two cases and review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol 2016; 122: e55-e59.

Shin HY, Park HJ, Choi YC, Kim SM. Clinical and electromyographic features of radiation-induced lower cranial neuropathy. Clin Neurophysiol 2013; 124: 598-602.

13.3.1 Nervus intermedius neuralgia

Pulec JL. Geniculate neuralgia: Long-term results of surgical treatment. Ear Nose Throat J 2002; 81: 30-33.

Riederer F, Sándor PS, Linnebank M, Ettlin DA. Familial occipital and nervus intermedius neuralgia in a Swiss family. J Headache Pain 2010; 11: 335-338.

Saers SJF, Han KS, de Rue JA. Microvascular decompression may be an effective treatment for nervus intermedius neuralgia. J Laryngol Otol 2011; 125: 520-522.

Tubbs RS, Steck DT, Mortazavi MM, Cohgen-Gadol AA.The nervus intermedius: A review of its anatomy, function, pathology, and role in neurosurgery. World Neurosurg 2013; 79: 763-767.

13.3.2 Painful nervus intermedius neuropathy

Günther M, Danckwardt-Lillieström, Gudjonsson O, Nyberg G, Kinnefors A, Rask-Andersen H, Ekvall L. Surgical treatment of patients with facial neuromas. Report of 26 consecutive operations. Otol Neurotol 2010; 31: 1493-1497.

Oldenburg MS, Carlson ML, Van Abel KM, Driscoll CL, Link MJ. Management of geniculate ganglion hemangiomas. Case series and systematic review of the literature. Otol Neurotol 2015; 36: 1735-1740.

Sweeney CJ, Gilden DH. Ramsay Hunt syndrome. J Neurol Neurosurg Psychiatry 2001; 71: 149-154.

13.4 Occipital neuralgia

Bartsch T, Goadsby P. Anatomy and physiology of pain referral in primary and cervicogenic headache disorders. Headache Curr 2005; 2: 42-48.

Boes Ch. C2 myelitis presenting with neuralgiform occipital pain. Neurology 2005; 64: 1093-1094.

Bogduk N et al The anatomy and pathphysiology of neck pain. Phys Med Rehabil Clin North Amer 2005; 14: 455-472.

Ehni G, Benner B. Occipital neuralgia and the C1-C2 arthrosis syndrome. J Neurosurg 1984; 61: 961–965.

13.5 Neck-tongue syndrome

Bogduk N. An anatomical basis for the neck-tongue syndrome. J Neurol Neurosurg Psychiatry 1981; 44: 202-208.

Elisevich K, Stratford J, Bray G, et al. Neck tongue syndrome: Operative management. J Neurol Neurosurg Psychiatry 1984; 47: 407-409.

Evans RW, Lance JW. Expert opinion: Transient headache with numbness of half of the tongue. Headache 2000; 40: 692-693.

Fortin CJ, Biller J. Neck tongue syndrome. Headache 1985; 25: 255-258.

Gelfand AA, Johnson H, Lenaerts ME, Litwin JR, De Mesa C, Bogduk N, Goadsby PJ. Neck-tongue syndrome: A systematic review. Cephalalgia 2017. doi: 10.1177/0333102416681570 [Epub ahead of print].

Lance JW, Anthony M. Neck-tongue syndrome on sudden turning of the head. J Neurol Neurosurg Psychiatry 1980; 43: 97-101.

Lenaerts M, Poblete R. Neck-tongue syndrome and its presentations. Cephalalgia 2015; 35: 143.

Lewis DW, Frank LM, Toor S. Familial neck-tongue syndrome. Headache 2003; 43: 132-134.

Orrell RW, Marsden CD. The neck-tongue syndrome. J Neurol Neurosurg Psychiatry 1994; 57: 348-352.

Sjaastad O, Bakketeig LS. Neck-tongue syndrome and related (?) conditions. Cephalalgia 2006; 26: 233-240.

Webb J, March L, Tyndall A. The neck-tongue syndrome: Occurrence with cervical arthritis as well as normals. J Rheumatol 1984; 11: 530-533.

Wig S, Romanowski C, Akil M. An unusual cause of the neck-tongue syndrome. J Rheumatol 2009; 36: 857-858.

Wong SL, Paviour DC, Clifford-Jones RE. Chiari-1 malformation and the neck-tongue syndrome: cause or coincidence? Cephalalgia 2008; 28: 994-995.

13.6 Painful optic neuritis

Du Y, Yang J, Li JJ, Zhou RW, He JF. Unilateral optic neuritis in a Chinese population in three centers. J Clin Neurosci 2011; 18: 902-904.

Fazzone H E, Lefton DR, Kupersmith MJ. Optic neuritis: correlation of pain and magnetic resonance imaging. Ophthalmology 2003; 110: 1646-1649.

Optic Neuritis Study Group. The clinical profile of optic neuritis. Experience of the Optic Neuritis Treatment Trial. Arch Ophthalmol 1991; 109: 1673-1678.

13.7 Headache attributed to ischaemic ocular motor nerve palsy

Kennard C. Disorders of eye movements I. In Swash M, Oxbury J (eds). Clinical neurology. Edinburgh: Churchill Livingstone 1991: 446-447.

Waind APB. Ocular nerve palsy associated with severe headache. BMJ 1956; 2: 901-902.

Wilker S, Rucker J, Newman N, Biousse V, Tomsak R. Pain in ischemic ocular motor nerve palsies. Br J Ophthalmology 2009; 93: 1657-1659.

13.8 Tolosa-Hunt syndrome

Cakirer S. MRI findings in Tolosa-Hunt syndrome before and after systemic corticosteroid therapy. Eur J Radiol 2003; 45: 83-90.

Cohn DF, Carasso R, Streifler M. Painful ophthalmoplegia: the Tolosa-Hunt syndrome. Eur Neurol 1979; 18: 373-381.

de Arcaya AA, Cerezal L, Canga A, Polo JM, Berciano J, Pascual J. Neuroimaging diagnosis of Tolosa-Hunt syndrome: MRI contribution. Headache 1999; 39: 321-325.

Goto Y, Goto I, Hosokawa S. Neurological and radiological studies in painful ophthalmoplegia: Tolosa-Hunt syndrome and orbital pseudotumour. J Neurol 1989; 236: 448-451.

La Mantia L, Curone M, Rapoport AM, Bussone G. Tolosa-Hunt syndrome: critical literature review based on IHS 2004 criteria. Cephalalgia 2006; 26: 772-781.

Odabasi Z, Gokcil Z, Atilla S, Pabuscu Y, Vural O, Yardim M. The value of MRI in a case of Tolosa-Hunt syndrome. Clinical Neurol Neurosurg 1997; 99: 151-154.

Straube A, Bandmann O, Buttner U, Schmidt H. A contrast enhanced lesion of the III nerve on MR of a patient with ophthalmoplegic migraine as evidence for a Tolosa-Hunt syndrome. Headache 1993; 33: 446-448.

13.9 Paratrigeminal oculosympathetic (Raeder’s) syndrome

Goadsby PJ. Raeder’s syndrome: paratrigeminal paralysis of the oculopupillary sympathetic system. J Neurol Neurosurg Psychiat 2002; 72: 297-299.

Shoja MM, Tubbs RS, Ghabili K, Loukas M, Oakes WJ, Cohen-Gadol AA. Johan Georg Raeder and paratrigeminal sympathetic paresis. Childs Nerv Syst 2010; 26: 373-376.

Solomon S. Raeder syndrome. Arch Neurol 2001; 58: 661-662.

13.10 Recurrent painful ophthalmoplegic neuropathy

Bharucha DX, Campbell TB, Valencia I, Hardison HH, Kothare SV. MRI findings in pediatric ophthalmoplegic migraine: a case report and literature review. Pediatric Neurol 2007; 37: 59-63.

Doran M, Larner AJ. MRI findings in ophthalmoplegic migraine: nosological implications. J Neurol 2004; 251: 100-101.

Gelfand AA, Gelfand JM, Prabakhar P, Goadsby PJ. Ophthalmoplegic ”migraine” or recurrent ophthalmoplegic cranial neuropathy: New cases and a systematic review. J Child Neurol 2012; 27: 759-766.

Lance JW, Zagami AS. Ophthalmoplegic migraine: a recurrent demyelinating neuropathy? Cephalalgia 2001; 21: 84-89.

Weiss AH, Phillips JO. Ophthalmoplegic migraine. Pediatric Neurol 2004; 30: 64-66.

13.11 Burning mouth syndrome

Bergdahl M, Bergdahl J. Burning mouth syndrome: prevalence and associated factors. J Oral Pathol Med 1999; 28: 350-354.

Eliav E, Kamran B, Schaham R, Czerninski R, Gracely RH, Benoliel R. Evidence of chorda tympani dysfunction in patients with burning mouth syndrome. J Am Dent Assoc 2007; 138: 628-633.

Forssell H, Jaaskelainen S, Tenovuo O, Hinkka S. Sensory dysfunction in burning mouth syndrome. Pain 2002; 99: 41-47.

Jaaskelainen SK, Forssell H, Tenovuo O. Abnormalities of the blink reflex in burning mouth syndrome. Pain 1997; 73: 455-460.

Lauria G, Majorana A, Borgna M, Lombardi R, Penza P, Padovani A, et al. Trigeminal small-fiber sensory neuropathy causes burning mouth syndrome. Pain 2005; 115: 332-337.

Patton LL, Siegel MA, Benoliel R, De Laat A. Management of burning mouth syndrome: systematic review and management recommendations. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007; 103 Suppl 39: 1-13.

Sardella A, Gualerzi A, Lodi G, Sforza C, Carrassi A, Donetti E. Morphological evaluation of tongue mucosa in burning mouth syndrome. Arch Oral Biol 2012; 57: 94-101.

Scala A, Checchi L, Montevecchi M, Marini I, Giamberardino MA. Update on burning mouth syndrome: overview and patient management. Crit Rev Oral Biol Med 2003; 14: 275-291.

Woda A, Pionchon P. A unified concept of idiopathic orofacial pain: clinical features. J Orofac Pain 1999; 13: 172-184.

13.12 Persistent idiopathic facial pain

Aggarwal VR, McBeth J, Lunt M, Zakrzewska JM, Macfarlane GJ. Development and validation of classification criteria for idiopathic orofacial pain for use in population-based studies. J Orofac Pain 2007; 21: 203-215.

Aggarwal VR, McBeth J, Lunt M, Zakrzewska J, Macfarlane GJ. Epidemiology of chronic symptoms that are frequently unexplained: do they share common associated factors? Int J Epidemiol 2006; 35; 468-476.

Forssell H, Tenovuo O, Silvoniemi P, Jääskeläinen SK. Differences and similarities between atypical facial pain and trigeminal neuropathic pain. Neurology 2007; 69: 1451-1459.

List T, Leijon G, Svensson P. Somatosensory abnormalities in atypical odontalgia: A case-control study. Pain 2008; 139: 333-341.

Pfaffenrath V, Rath M, Pollmann W, Keeser W. Atypical facial pain – application of the IHS criteria in a clinical sample. Cephalalgia 1993; 13 Suppl 12: 84-88.

Sardella A, Demarosi F, Barbieri C, Lodi G. An up-to-date view on persistent idiopathic facial pain. Minerva Stomatol 2009; 58: 289-299.

13.13 Central neuropathic pain

Abhinav K, Love S, Kalantzis G, Coakham HB, Patel NK. Clinicopathological review of patients with and without multiple sclerosis treated by partial sensory rhizotomy for medically refractory trigeminal neuralgia: A 12-year retrospective study. Clin Neurol Neurosurg 2012; 114: 361-365.

Cruccu G, Biasiotta A, Di Rezze S, Fiorelli M, Galeotti F, Innocenti P, et al. Trigeminal neuralgia and pain related to multiple sclerosis. Pain 2009; 143: 186-191.

Jensen TS, Rasmussen P, Reske-Nielsen E. Association of trigeminal neuralgia with multiple sclerosis : clinical pathological features. Acta Neurol Scand 1982; 65: 182-189.

Putzki N, Pfriem A, Limmroth V, Yaldizli O, Tettenborn B, Diener HC, et al. Prevalence of migraine, tension-type headache and trigeminal neuralgia in multiple sclerosis. Eur J Neurol 2009; 16: 262-267.

13.13.1 Central neuropathic pain attributed to multiple sclerosis

Mills RJ, Young CA, Smith ET. Central trigeminal involvement in multiple sclerosis using high-resolution MRI at 3 T. Br J Radiol 2010; 83: 493-498.

Osterberg A, Boivie J. Central pain in multiple sclerosis – sensory abnormalities. Eur J Pain 2010; 14: 104-110.

Osterberg A, Boivie J, Thuomas KA. Central pain in multiple sclerosis – prevalence and clinical characteristics. Eur J Pain 2005; 9: 531-542.

13.13.2 Central post-stroke pain

Bowsher D, Leijon G, Thuomas KA.  Central poststroke pain. Correlation of MRI  with clinical pain characteristics and sensory abnormalities. Neurology 1998; 51: 1352-1358.

Fitzek S, Baumgartner U, Fitzek C et al. Mechanisms and Predictors of chronic facial pain in lateral medullary infarction. Ann Neurol 2001; 49: 493-500.

Hong JH, Bai DS, Jeong JY, Choi BY, Chang CH, Kim SH, et al. Injury of the spino-thalamo-cortical pathway is necessary for central post-stroke pain. Eur Neurol 2010; 64: 163-168.

Kalita J, Kumar B, Misra UK, Pradhan PK. Central post stroke pain: clinical, MRI, and SPECT correlation. Pain Med 2011; 12: 282-288.

Klit H, Finnerup NB, Jensen TS. Central post-stroke pain: clinical characteristics, pathophysiology, and management. Lancet-Neurology 2009; 8: 857-868.

MacGowan DJ, Janal MN, Clark WC, Wharton RN, Lazar RM, Sacco RL, et al. Central poststroke pain and Wallenberg’s lateral medullary infarction: frequency, character, and determinants in 63 patients. Neurology 1997; 49: 120-125.

Tuveson B, Leffler AS, Hansson P. Influence of heterotopic noxious conditioning stimulation on spontaneous pain and dynamic mechanical allodynia in central post-stroke pain patients. Pain 2009; 143: 84-91.